Vulcan-74 - A 6502 Powered Retro MegaProject

[BigEd]

Two 50 pound components? A couple of handles and you've got yourself a luggable! Great stuff.

[Oneironaut]

Thanks!
Side handles... not a bad idea.

BigEd wrote:

Two 50 pound components? A couple of handles and you've got yourself a luggable! Great stuff.

[ttlworks]

Two 50 pound components.
I interpret this as 2 * 50 * 0.454kg = 45.4kg.

Probably the "dry weight" only.
Hmmm... side handles...



That's quite an idea:

hss.png (31.58 KiB) Viewed 1708 times

Welding the frame for a casing from something like HSS structural steel,
then to leave four holes in the casing.

So it would be possible to stick two (less thick) HSS shaped profiles through the frame for carrying the casing around.
Plus something like 3D printed plastic handles that could be mounted in a reliable way (flat head screws ?) to the ends of these two profiles.
Edit: hey, your bicycles happen to have plastic handles...

Maybe it's too late to implement the idea with this project... but probably with the next.

[Oneironaut]

I was thinking of something more like conventional recessed handles,, but I do like the idea of a royal entry.

[ttlworks]

Royal ergonomics.

Nice picture.

[Oneironaut]

I was going to leave this for a later post, but Vulcan-74 is also going to include a reel-to-reel 64K paper tape boot system.
This will be a stand alone unit that reads a a long sequential series of binary marks on a roll of paper.
Instead of punched holes, I intend to use laser printed paper or possible thermal paper.
The entire "boot drive" will also be mechanical in design and probably add another 50 pounds!

I will probably only use the tape loader for the OS / IDE boot system.
Games & demos will be graphics heavy (many MBs) , so loaded via serial.

Why??.... cuz it's cool, and I like to build stuff!

Brad

[Dr Jefyll]

Oneironaut wrote:

Why??.... cuz it's cool, and I like to build stuff!

DIY is fun, fer sure. But if you run short of time and want a manufactured paper tape reader, just let me know -- I have two in my garage!

( Back in the day, I equipped my KIM-1 to read and write paper tape. )

[ttlworks]

Ja, but thermal paper isn't quite the thing: it deteriorates in heat and sunlight.

IIRC Konrad Zuse had re_used old film rolls as punched tape.

Wait a minute: with a reasonable abount of energy, laser printing on thin metal film rolls (or metalized film rolls) also might work.

Hmm... sort of reminds me: feed units for Bruderer BSTA 510 high speed press and such.

[Oneironaut]

Interesting ideas!
I will post my concept when I have time to complete the model, but this is what I have designed so far (in theory)...

8.5 X 11 paper is printed with 64 bits across, and 128 rows, for a total of 1K per sheet.
I intended to tape 64 sheets together end to end and then roll them up on custom 6" rolls.
The reader would scan a row at a time at a feed rate of 1 sheet every 2 seconds for a total 64k load time of 32 seconds.

Using a standard laser printer means making program easily and inexpensively.
For the reader, I was thinking of an old CCD array from a scanner, I have used these with FPGA's before with success.
Of course, here, I will be going old-school logic!

I would be interested in seeing the KIM-1 reader. Did it handle 64K?

Brad

[Dr Jefyll]

Oneironaut wrote:

I would be interested in seeing the KIM-1 reader. Did it handle 64K?

Well, there are two readers, one very fast and the other, seen below, moderately slow (stepper motor powered). Both use parallel interfaces, and theoretically the host computer's software could ask for any amount of data. But these particular readers don't have reels, meaning they're somewhat of a nuisance if you frequently need to load large programs (ie, long tapes). But for occasional use they're fine, even with a long-ish tape.

The infrastructure I created for myself revolved around a Friden Flexowriter given to me by a client. I used to send EBCDIC (not ASCII) characters in parallel to a 6522 attached to the KIM-1, and miniature relays output the 90VDC levels which drove the solenoids in the Friden. The latter served me both as a printer and as a paper tape punch.

I used the stepper motor powered reader, and IIRC it too could connect to the 6522. But there was also a highly perverse hookup that hijacked the KIM-1 keypad matrix. Somehow I had a 32x8 TTL PROM that input EBCDIC from the reader and simulated the corresponding keypresses on the KIM. So, if there was some frequently used ditty that required me to enter a long, tiresome sequence on the KIM keypad, I could instead just type that on the Friden once, and it'd output a tape that would effortlessly cause the KIM to hallucinate the sequence as often as desired.

I know it sounds Rube Goldberg-ish, and I may as well admit there was "a little bit" of youthful creativity (ie, problem seeking) at work. OTOH I had no access to non-volatile storage other than cassette tape, so the system was genuinely useful to a degree. Sorry if I've gone overboard with the OT reminiscing!

-- Jeff

[Oneironaut]

Very cool!

I am mainly working around a few set of rules on my reader...

- Must load 64K in under 2 minutes.
- Must be able to make programs quick and easy using off the shelf materials as storage medium.
- Must use retro era parts I have here with the exception of the "read head", which I will allow one modern component.

So far the end-2-end printer paper made on a laser printer seems to answer all of this.
I was also considering the following storage medium...

- Roll of packing paper burned via laser, making the device read and write.
- Large diameter lexan disc burned with laser. This would need to be about 2 feet in diameter.
- Some kind of flagging tape roll burned via laser. Less bit width, but could be faster RPM read.

So far the standard printer paper seems best. The only effort is to tape the sheets end-2-end, but that could be done in half an hour. The medium should be robust enough to last decades.

If only laser printer tech. allowed for roll printing then this would be so easy!
Of course, there is that rule.... must be cheap, easy, and made from parts already sitting in this room.

I am again considering a roll of paper and a 1 watt blue laser as a R/W device.
With a simple lead screw and a few steppers, it would be no problem at all to make a continuous roll burner.
Could probably get 32 1/8" holes burnt across a sheet a a decent row density.

That project comes after Vulcan-74 has it mainboard wired though, so no rush!

Brad

[ttlworks]

There is adhesive aluminium foil for front panels, normal laser printers are supposed to be able to print it like paper.

I'm not sure, if Avery L6013 is available in Canada.

[Dr Jefyll]

Oneironaut wrote:

- Large diameter lexan disc burned with laser. This would need to be about 2 feet in diameter.

Hmm, if the disc were 12 inches in diameter then maybe a repurposed phonograph turntable could be used to advantage. Nice bit of retro appeal there! But obviously the bit density would need to be much higher.

Maybe the turntable idea could be combined with your idea of packing paper burned (and later read) via laser... But a rigid material would be easier to keep flat -- and for high bit density you'll need the disk to have a high degree of flatness (unless your optics include an active focus mechanism).

[ttlworks]

Tesafilm(TM), and Tesa ROM.



Back in 1998, two scientists in Mannheim\Germany had tinkered with laser writing of Tesafilm(tm) rolls, just for the fun of it.
If I'm understanding it correctly, they had thoughts about later (holographic ?) reading/writing micrometer sized dots on the foil without unrolling the adhesive Tesafilm.

But no Tesa ROM was introduced to the market, they only had started Tesa Scribos instead.

Found some old pictures which don't tell us too much here.

;---

Something different: Sony paper disc. //25 GB disc containing approximately 51% paper by weight.

[Oneironaut]

This is interesting as well...

https://hackaday.com/tag/wire-recorder/