Hi Everyone,

I have built a KIM 1 on breadboard and I am using a 1MHz Rockwell 6502 part, everything is now working as it should, I can even download KB9 basic from cassette tape at x3 speed and no problems everything works okay.

Next up, I have some W65C02 parts available to me and I decided to try one, I used a pullup on the Bus enable and open circuited the Vector pull pin (VP pin 1), when I power up Kim runs and communicates with my tty emulator no problem, however when I try and download KB9 basic from tape, it loads okay but when I try and run it I get garbage. Note, I tried a good couple of times and always the same with the W65C02, replace it with a R6502 and everything works great.

The funny thing is, it runs KIM monitor rom okay, but not KB9 basic, does anyone know what is wrong or is the W65C02 just simply not 100% backwards compatible?

Also, I'm based in the U.K., does anyone know of a standard 6502 supplier around here?

Cheers All

65XX part sources

viewtopic.php?f=1&t=1953

Distributors from Western Design Center:

http://www.westerndesigncenter.com/wdc/distributors.cfm

You may also be able to get them from Western Design Center directly but you have to get a quote.

Hi Chuckt,

Thank you very much for the valuable links, I tried loading Microsoft KB9 basic again but it simply will not work with the W65C02??, strange cant see why?

Managed to get x7 R6502 chips off Ebay@£2.5/chip

It seems original 1MHz 6502's work great, shame about the WDC types though.

Doesn't the 65C02 get rid of the "undefined op codes" of the NMOS? Could the BASIC possibly be relying on some undefined op codes?

I think that the problem may be that the Rockwell part has some branch on bit set/reset instructions and the WDC doesn't have those opcodes.

Welcome!
Kb9 basic can be found here: http://retro.hansotten.nl/index.php?page=micro-kim
Probably we need an emulator or at least a disassembly (or maybe you can do something with single-step or breakpoints...)
Cheers
Ed

The WDC part has all of them and even a little more (STP & WAI) than the Rockwell 65c02 did; but he's talking about the non-CMOS Rockwell one. It sounds like the BASIC used some undefined op codes of the NMOS processor which the later CMOS ones replaced with well-behaved & more-useful ones. The CMOS op code table is still not full like the 65816's is, but the unused spots of the W65C02S effectively become NOPs.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

Quick question - which version of Basic have you tried to run? I see three versions in the zip file.
Cheers
Ed

Hi Everyone and Ed,

Gee, all the replies thanks, it would seem KB9 uses some undefined op codes then?, both precessors run KIM 1 operating rom no problems, however when I try and run microsoft basic v1.1 KB9 using the w65c02 cpu then KB9 v1.1 doesn't work but works on the Rockwell part no problems. Also, when I try run the other two basics V2+3 it's no go even with the Rockwell part.

I'd just like to point out that I have written a few programs, in basic, running on the Rockwell part, saving to tape and reloading from tape is absolutely fantastic.

Has anybody here run the other two basics V2 and V3 from the zip file successfully?

Cheers Everyone
Commie

Ya know, that's not something I'd ever thought I'd hear nowadays. What's the KIM format? 110 baud equivalent or so? Beats typing it in, for sure.

Hi Whartung,

I can load KB9 in just under 5 minutes, using KIMTAPE utility program saved at x3 speed, normal KB9 tape load time is around 16 minutes and KB9 is around 11kbytes in code length.

Cheers
Commie

So apparently the normal KB9 speed is 110bps! Wow, I didn't know any of them went that slowly. The ultra-cheap audio cassette modem I made for a product in the 1980's never lost a bit at 300bps, and very rarely at 600bps, although I could have changed things a bit (increased frequencies used, especially the lower one) to make it more suitable for 600.

_________________
http://WilsonMinesCo.com/ lots of 6502 resources
The "second front page" is http://wilsonminesco.com/links.html .
What's an additional VIA among friends, anyhow?

_________________
x86?  We ain't got no x86.  We don't NEED no stinking x86!

Yes, indeed, cassette download speed is ultimately governed by the bandwidth of the tape, I did a few tests using my RIGOL siggie gen and found that the tape bandwidth is limited to around 5kHz, KIM 1 saves at 3700Hz so there isnt much left in terms of spare bandwidth. High speed programs work by reducing the number of 3700 Hz cycles, normal being 9 cycles.

Has anybody managed to run KB9 V1.2 and V1.3 or V2 & V3 on there KIM's?

Cheers
Commie

No, but I recall using something similar. So, I reached for my old, dog-eared copy of The First Book Of Kim and flipped to the article entitled Hypertape by Jim Butterfield.

The article describes a speedup for the KIM-1 cassette routines. It says, "You can load a full 1K in 21 seconds." (Notice the language there -- "a full 1K." Don't you love it? 1Kbyte was all the memory an unexpanded KIM had!)

Anyway, I thought Hypertape may be of interest to you, Commie, as it is significantly faster than the times you mention for KIMTAPE. (It's not limited to 1K of course.) I used Hypertape myself back in the day, and found it satisfactory -- a boon, in fact. Heck! Anything that could lessen the agony of cassette storage was a boon!

-- Jeff

edit: linkify the book title

_________________
In 1988 my 65C02 got six new registers and 44 new full-speed instructions!
https://laughtonelectronics.com/Arcana/ ... mmary.html