Project-28 - A somewhat Minimal 6502 system

[barnacle]

For reasons I do know know, I have never even thought of arranging the port outputs as a single row of pins. I usually end up with a pair of 2x6 headers...

Love the round corners!

Neil

[drogon]

barnacle wrote:

For reasons I do know know, I have never even thought of arranging the port outputs as a single row of pins. I usually end up with a pair of 2x6 headers...

Love the round corners!

Neil

I use Fritzing and it has round corners as a standard PCB option, but it's easy to upload your own design which I've done in the past.

And I know people will tell me to us something other than Fritzing, but it works for me and I've never had the time nor inclination to use e.g. KiCAD.

-Gordon

[drogon]

BigEd wrote:

Really nice!

Thanks.

Here's a wee video of that GPIO test program running:

https://youtu.be/jmwvpzrQIlk

-Gordon

[GARTHWILSON]

barnacle wrote:

For reasons I do know know, I have never even thought of arranging the port outputs as a single row of pins. I usually end up with a pair of 2x6 headers.

Are you sure it's 2x6?  2x5 and 2x7 are standard IDC sizes, but not 2x6.

[barnacle]

Yeah, but I've never quite got the stage of actually using the pins with a wired connector...

Neil

[drogon]

After some more code wrangling, and currently at the expense of the DPOP command (for now... I have added in code to enable "pins" 16 and 17 to be the CA2 and CB2 output pins.

Video test with 18 LEDs here:

https://www.youtube.com/shorts/pLJLw-KT6cI

Ugly code here:

Code: Select all

   10 FOR P = 0 TO 17 : PM P,1 : NEXT P : REM All output                                                   
   12 FOR P = 0 TO 17 : DW P,0 : NEXT P : REM All off                                                      
   14 LED = 0                                                                                              
   16 DO : UNTIL BTN                                                                                       
   20 D = 1                                                                                                
   90 DO                                                                                                   
  100 REM Outwards                                                                                         
  110 FOR P = -3 TO 19                                                                                     
  120 H = P+2 : T = P-1                                                                                    
  140 GOSUB 800                                                                                            
  160 NEXT P                                                                                               
  300 REM Inwards                                                                                          
  310 FOR P = 19 TO -3 STEP -1                                                                             
  320 H = P-2 : T = P+1                                                                                    
  340 GOSUB 800                                                                                            
  360 NEXT P                                                                                               
  399 UNTIL BTN                                                                                            
  400 END                                                                                                  
  799 REM Light the Head                                                                                   
  800 IF H <  0 GOTO 820                                                                                   
  805 IF H > 17 GOTO 820                                                                                   
  810 DW H, 1                                                                                              
  820 REM Extinguish the tail                                                                              
  830 IF T < 0 RETURN                                                                                      
  840 IF T > 17 RETURN                                                                                     
  850 DW T,0                                                                                               
  860 RETURN                                                                                               
  899 REM Small Delay                                                                                      
  900 Z = D : DO : Z = Z -1 : UNTIL Z < 0 : RETURN

-Gordon

[GlennSmith]

Really cool card, and a quite amazing feat to get all that squeeze!
Well done.

My native PLASMA compiler/assembler is nearing completion, soon I'll be working on the 'picocomputer' V2 board to add more I/O. Currently building a brand new office/laboratory - so I'm hacking bricks and timber at the moment...

[drogon]

Musing idly about my this project with it's 4KB of ROM and I wondered if with todays technology if it would be possible to auto-create every possible program for it...

The short answer is no.

The long answer is that with 4096 bytes, or 32768 bits that's 2^32768 possible program combinations.

Or this number:

```
14154610310449547890015530277449516013481307114723881672343857482723\
66634240845253596025356476648415075475872961656126492389808579544737\
84888193829625087319174392779354491301105016265127795702984696021178\
32429335212075454134849698568518511412885151632014829953890550974606\
22098635675003353929224278582935664416262572773308153277514346480313\
37198861262948148356243817892895886777785007219831617484125195559099\
66720186450936408508036796302203672013838448667914492847375182628131\
23083439037243678440420897139923778278952770312318778329004894547065\
48907759683539601715360317005037130201476244387270111137955448430971\
86623068837760104753484414936004919434790412719929201953319830649301\
06164727241438940877685164658948654886171641124473975626241632750150\
12665536998102129357006604230548248604088316563586283572863704605835\
24037560857456912394738978919990859763452037046599671574272395358365\
07133656908815246080139195569461072006301590372954830738644391138016\
06534413113120760426405389744082890466204718323437754742728769194174\
15359465108829909044778631854737985283880604575689279436339239288726\
81927502029572963130840854853739937076881035646179383055483433876051\
40203761442474890296901815918651981105154536796710376718281970913547\
90191316833093307973744081973398315272390407159081122130951267707176\
06001288898889370710896248862361503869205214536908258196921765593065\
32539283633214259441113460347550936602814569030635060185929526129626\
33310186822763175677495345710587722355676795569202407891090705212539\
87131031263902293034744367356932509952188828475362311316445284228640\
48942180926373842363093124302491458786392813471918610416466060535600\
15919627786463782954136597707826469792362890626164424180715710392825\
51289348848274522893059561717860194034698241804887531275078109603637\
16049590757999536641963641702892757339167058079681852607422609501437\
51894385792160716775407660856056041061230366696674346777234726755644\
58991671268414100801031453917736665947284956674884035306621286465183\
79869385259980332461986518185624442207923368729450853640852108741887\
39084982027105970804744802498188580114909305185127137988036291016387\
16278578874145214429026186276602289012484526830076647356828764878327\
72671981642867890420794445689439318598309034704517688673232625391229\
76495244398804037014305667613803599255585227182019542875175873672475\
10777678934664472548647787048306330770862370015525858005479756471499\
22724490114280574976956418475321196722322621296416567885660489241698\
49150974229605341223334538769812792435657663917963116051492226283282\
55333061543877525846029404507128890053189442527544665141513571136187\
12687491460166975039248610050756844204683178063103254057407794427445\
42280876392417368185051637599103651319906329474629932045852181224319\
92323864244947394390438656356424037471932484452186545692102503479070\
59995382316519421101969676057526442680284830303180430573353222805018\
02860341751689188274606260422686582951407069150471890494925789966504\
94005882337071150004868956193406593184838633694068409823903437144417\
37603917423501105322884685142421795517290291865100361098410840265092\
93593963056343130470887251130390768119400901098555782859378291642135\
76612822210347957745947331047482525346602542653176899809278808232796\
55753183215024976925360066790226802966170014963286854195626611952804\
24865340147787798469817610331550072627301626759545202218873847103870\
51721829271917592295057169589539706361671082094809405871790468623234\
89591479646439001925916751377186483286903601564554219500845609861503\
83480284008030058019449571562827463795394702506037554653587862814760\
86044567893715130635914946085361612372742732638037372287633897118303\
25003635589775820956901024605156342910925586493824552455020058021827\
43148097380750227756512203741052272159062052927519186670604753285932\
25367793061070422108733800983855507591806413460964585595316359971179\
28428360473146866854548476138174759163973645341989644932348639703077\
63977612025904676375054733902222494567240932386825577627818395309382\
33751281999608711356147835655195236666056355678841889862284014674059\
05299517022071140444501276664220331459237171259487796834326521023279\
81350232991173181917703651238070867043818097596022601516129968969942\
94186084475619138121455294389585874237791634701296124550179672059485\
83825644584653059913766248084134437650398924463334501607088719812042\
14355757262371893121618180215480063895011823934417121420449530722640\
16676799011624620312246468554654371544717355227740157629086739710675\
84520999213334203514403896106589265339218287562293267006779843393489\
17095198778507942194914479881601719323310064956202800941494643794501\
53085406225081471879585894087916092141623752345112751067703166403681\
16233192029174084738895763231105334242615294732401162792222587853993\
50229746160627748391104890800941749728410681020066456774992937690913\
62853719300958775222088670909723895414866464400756314470281962034276\
53151254400972617464939993758173971811798241736098595825946848543658\
67336866597710306776646779054015223600418924819514541353605409174110\
98412286723830672712910603386748136348878056545746112142111116659985\
78239827562712244941430714074940488406075386370602428103148553866613\
33328355978175146163317281189821806288236576686680996217998420111580\
20767772792912298768785614574416019320546196793486018677884550715870\
60800498882997814896698077013688435322694985365454165583702949801703\
10859436604404660760194794351810454368978453510487884401022686777982\
57134774081674357195358847761226603653040273985441982221318087815835\
10731757121184121582560645334852109793641352029599826075104077870374\
03663098719991147174410691828257829962994116230874150089109413032841\
82131584799816210728034255555687956785287887098941927737599159824398\
52757342311772825283976891914501811799559794628226494652374169118085\
84411943733870989695301268340149236566278491290621891455728702122259\
09464530919531634090206371146321663797279805760028495288084848179380\
05393143560418251751660082393673791991597410359116763889887175401847\
01725892349893970518930285743652888903037802391946225382155322127355\
55299397542845350629361560347195459286729561168235383428930828378887\
67819759062411037226733875666841489952613848086674711483141468757969\
16360205860136356755590334886497210622441427879604040569613061760229\
81242840984825421797150393909713884990708008654327558025619074213270\
71425243151517163899450572014434750218584852812900005562970342269542\
50472095181775771285113154920596137223667246153439683573329241911780\
41956753132941596322101250417068813977303498033940613791099720174786\
77384469673403401026913955387821238710850815862283973359363491897561\
66133682438828083915092448068093378829653387015455046915895176504722\
39580754189547649790038026506707709763098148746524031013800531890876\
85822736050167616187466194643164792957255599296729855347115269347145\
24801198976081733367532601244525108153334164093570296332651726142036\
63326409976153102467083379129588112837280711111346490898947808402062\
40122896319416271165742299842926357927651541400097905374066273381663\
29815085351285184402580067823922888609038232074368207930418819070937\
91874917635829854808150640894907127600430185202301457398493533111918\
99410085375377195629343016256601136116316895346218801023181900021366\
97804478568712485643775845090858887978837475383091818107006150322255\
63091016689474780253412571338625581817921061549352557588323659562675\
65056353518614475443355653974709832264360954248612051291746370671305\
90642307629243536179720534925271191926581718513459577007725718419981\
76036269399889012480745075924980479390349332734102774400008120073461\
54054057105150697100390462348434476200512634590546589381789537792813\
95965499367201004900133759566058892007675966880659610760034720055858\
90222594655010430123127351665316862663484785966446263740624564875351\
64078092370300686810744079027168293604330487357964898997857175489884\
07891844801295704469910295047586163931064875233213125074540368086672\
10073602144290050619610614738139543285649346986393213102456863793665\
51253365593194179053761902060473060144318125066201968749171154736059\
71178569772408171100397371533552124547459077871311795786564705675350\
50192702347739653312290522505871612897990429961857550031033665725647\
98798275186840729473043731950533578242529032442799430837496080668443\
54164459078171071682983429451829855941112814994724957495016424180427\
34681158560450241309279063816746067016274795461832774699007774423895\
74867761539584849376567227195727866454634316160912681002825421465963\
36252239345089316917285840283423566693326354580799571478337895016968\
35781748234884919093574276330354577841975249603899105407104895787598\
26363067920662779643375404559740917650243886760053701687916991447475\
48400243119221696473883799528025238470801024392851125657516777263732\
01688403254466789070713575214256192452449029110040537994627424532403\
62017988005651872121910877137407363811871907321136729551437670859653\
72942045440999035907543716561786569601702176758321532681645916740045\
00239073743502648099105624548587493544825479270589742494495181223722\
32969334546863930699052311899564056704253136957713111315902738180807\
13469916045139064503982194263008992046624354925784856665539744927231\
73859777485412927016068341515517437115137050372750279278548332799193\
79940015416644280142731007653702011993607349522197479193975984616894\
20553973573482781780504410244900058938182569586653889712013229316805\
73846084525016332224646866617490832496084991690171583029352609836490\
90811346466834382998535159055294528437257397829548509795089307242351\
86059820854871544701550252690258540446464965724484952253430962618963\
78931482883286657508859228868487844184479087538453974144187004884366\
56125672340477219084758600854396134907113119170894329533766438418453\
27746615032459102574519235156077115597054781325560401976634149118851\
43697985464807309297002910250505302287769412337441199360424519160716\
55289088281679637829688164182798145303520723375206351878277849374382\
77081099134931629321824276272610462801682699580775411226681046337123\
77856

```

So not this year, at least.

-Gordon

[BigEd]

I do hope you did that calculation on some flavour of 65xx!

[John West]

There's a question... is it possible to do that calculation on a 6502 with only 4K of RAM (and no other storage)?

[drogon]

BigEd wrote:

I do hope you did that calculation on some flavour of 65xx!

I wish I had - sadly my own calculator (APRICOT) doesn't yet support arbitrary precision numbers. Unix bc for the win...

-Gordon

[drogon]

John West wrote:

There's a question... is it possible to do that calculation on a 6502 with only 4K of RAM (and no other storage)?

A good question... The result is slightly under 10,000 digits, so even packing them BCD, 2 digits to a byte would need over 5KB of storage... Maybe it depends on the precision you actually need - It's approximately 10^9864 and that may be represented in less digits but I don't know where/when you'll start to lose accuracy.

All you need is time..

-Gordon

[BigEd]

Mmm, yes, calculating 2^32k as a decimal with only 32k bits... we're one bit short before we even start! The carry bit might be brought into play...

But the very first step (in one approach) is to divide by 10, which knocks three bits off. Still a bit tight, with no stack and no zero page to spare!

We have lots of program space though. So we could proceed by dividing by a million, for example, which would free up two bytes. Hmm... and in any case this gives us the digits in reverse order, which is all a bit backwards.

I'm beginning to think this is going to be quite a squeeze! I withdraw the question, m'lud!

[drogon]

Life in the Slow Lane...

Doing more testing and writing some code for my Project-28 system, another mention in another place about a "tiny" Life got me thinking of writing one in my TinyBasic on the Project-28 board...

There is nothing special about my implementation, however it's split over two programs. One to let you enter the initial pattern (No fancy editor here!) and one to run the game. It's not fast, but it was never going to be. It was also a good test of using an array (*cough*) or direct memory peek/poke via the indirection operators.

It needs 2 programs as the grid array at 40x25 needs 1000 bytes of RAM and a naive approach uses 2 arrays, so almost 2KB needed - out of the 3.5KB we have, that makes it very tight - especially as I used a particularly simple, but perhaps 'dumb' way to get the initial pattern in-place...


The setup code is:

Code: Select all

NEW

0REM Game of Life: Setup

1GOTO100

REM - Store data into RAM - 0,0 is top left.
REM	Code at the top to try to make a tiny bit of speed increase

2J=(24-L)*40+X:PR"+";:FOR I = 0 TO 39:?(J+I)=?(A+I):NEXTI:L=L+1:RETURN

REM Main code is here

100GOSUB 800
110GOSUB 900

120PR "" : PRINT "Setup Complete." : VDU 7
130REM CH 7
140END

REM Initialise Variables

800A = TOP
810X = &C00
820Y = &800
830FOR I = 0 TO 25:VDU 32:NEXT I:VDU93,13,91
835Z=2:L=0
840RETURN

REM =================================================================
REM ===  Edit Below, each line must be exactly 40 characters and
REM ===    we have 25 lines; 0-24.
REM ===  Note that we MUST leave the top, bottom and side
REM ===    edges of the grid clear. This simplifies the otherwise
REM ===    very slow processing...
REM =================================================================

REM    0         1         2         3        3
REM    0123456789012345678901234567890123456789
900$A="                                        " : GOSUB Z
901$A="    *                         **        " : GOSUB Z
902$A="     *                        **        " : GOSUB Z
903$A="   ***                                  " : GOSUB Z
904$A="                                        " : GOSUB Z
905$A="                *             *         " : GOSUB Z
906$A="                              *         " : GOSUB Z
907$A="                              *         " : GOSUB Z
908$A="                                        " : GOSUB Z
909$A="                                        " : GOSUB Z
910$A="                                        " : GOSUB Z
911$A="                                        " : GOSUB Z
912$A="                                        " : GOSUB Z
913$A="                                        " : GOSUB Z
914$A="                                        " : GOSUB Z
915$A="                                        " : GOSUB Z
916$A="                                        " : GOSUB Z
917$A="                                        " : GOSUB Z
918$A="                                        " : GOSUB Z
919$A="                                        " : GOSUB Z
920$A="                                        " : GOSUB Z
921$A="                                        " : GOSUB Z
922$A="                                        " : GOSUB Z
923$A="                                        " : GOSUB Z
924$A="                                        " : GOSUB Z

REM =================================================================
REM === END OF USER EDITABLE DATA
REM =================================================================

925RETURN

Note that it may at first appear a bit odd - there are REM statements with no line numbers - that's for a couple of reasons, but mostly to save space in the program - I am using an external editor to create this then I send the file to the Project-28 SBC over the serial line. This was a trick used in early TinyBasic systems where you might edit a paper tape with the 'source' externally then feed it into the system to run it.

Also; as the serial is bit-banged software then it's effectively half duplex, so I have a command (Press Ctrl-O) that disables all output which allows it to take 'keyboard' input at full speed (9600 baud). Another Ctrl-O enables output again. It's a bit fiddly but has proven to be very effective

(oops.. more editing as I hit submit rather than preview!)

so this pokes the data into RAM at a known fixed location near the top of usable memory so that when the Life program loads and runs it's not overwritten.

This is the actual Life code:

Code: Select all

NEW

0REM Game of Life
1GOTO100

REM Store status into new grid

5REM?D=Q:VDUQ:RETURN
5?D=Q:RETURN

REM Check the 8 cells surrounding cell at Line N and Column C
REM	S is our test cell address
REM	D is our new  cell address (Destination)
REM	Q is the value to store
REM	K is the surrounding cell count

10S=N+C : D=P+C : Q=32 : K=0

11IF?(S-1)<> Q K=K+1
12IF?(S+1)<> Q K=K+1
13IF?(S-39)<> Q K=K+1
14IF?(S-40)<> Q K=K+1
15IF?(S-41)<> Q K=K+1
16IF?(S+39)<> Q K=K+1
17IF?(S+40)<> Q K=K+1
19IF?(S+41)<> Q K=K+1

  REM 0 or 1 neighbour - die

20IF (K=0) OR (K=1) GOTO 5

  REM 2 neighbours to a live cell? Lives on...

25IF (K=2) AND (?S=42) Q=42:GOTO 5

  REM 3 neighbours? If live then lives on, if no life, then create

30IF (K=3) Q=42:GOTO 5

  REM 4,5,6,7 or 8 neighbours - die

35GOTO 5

REM Horizontal Line

40PR "+";:FOR I = 1 TO 38:PR "-";:NEXT I:PR "+":RETURN



REM Start here
REM =========================================

100GOSUB 900

REM We avoid the outer edge on all sides
REM	N is the current Row start
REM	P is the   new   Row start

110DO
120  FOR I = 0 TO 25:VDU 32:NEXT I:VDU93,13,91

130  FOR L = 1 TO 23
140    PR "+"; : N = (24-L)*40+F : P = (24-L)*40+T
150    FOR C = 1 TO 38:GOSUB 10:NEXT C
160  NEXT L
170  A=F:F=T:T=A
175  VDU13
180  G=F: GOSUB 700
190  PRINT "Generation: ",Z : Z=Z+1
200UNTIL BTN
299END


REM Print current grid
REM	G: Start address of current grid

700REMN = G + (24*40)
710GOSUB 40
720FOR L = 1 TO 23
730  PR "|"; : N = (24-L)*40+G
740  FOR C = 1 TO 38 : VDU ?(N+C) : NEXT C
750  PR "|"
760NEXT L
770GOSUB 40
780RETURN


REM Initialise Variables

900PR "Initialising... ";
905A = TOP
910X = &C00
920Y = &800

REM From & To

932F=X : T = Y : Z = 1 : REM From and To, Generation

REM Wipe destination grid

930D = Y
933FOR L = 0 TO 24
934FOR C = 0 TO 39
940?(D+C)=32
950NEXT C : D = D + 40 : NEXT L
960PR ""
970PR "From:" : G=X : GOSUB 700
980PR "To:"   : G=Y : GOSUB 700
985I=GET
990RETURN

It's not fast and it never was going to be. It's taking about 57 seconds per generation, so from this:

Code: Select all

+--------------------------------------+
|   *                         **       |
|    *                        **       |
|  ***                                 |
|                                      |
|               *             *        |
|                             *        |
|                             *        |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
+--------------------------------------+

To this, 80 generations later:

Code: Select all

+--------------------------------------+
|                             **       |
|                             **       |
|                                      |
|                                      |
|                             *        |                    
|                             *        |                    
|                             *        |                    
|                                      |                    
|                                      |                    
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                                      |
|                       *              |
|                        *             |
|                      ***             |
+--------------------------------------+
Generation: 80

Was just over an hour.

Lots of fun!

-Gordon

[barnacle]

Nice to see that Mr Conway hasn't been forgotten, Gordon!

I don't think I can do that on mine; no peek or poke. But let's see how much memory is left...

Neil