Hi there,

I'm new to these particular forums. I've been a vintage computer collector for years.

I recently purchased an Ohio Scientific 300 board with a white ceramic 6502 on it. The date code is 3875, and I was wondering if this likely had the 'famed' ROR bug. The 300 is a slide-switched based single board computer, I don't know if it'd be possible to give an instruction to test it out.

The other question I have, just for my own curiosity, is if anyone knows what the first 'commercially available' 6502-based computer was. This OSI board appears to have come out in late 1975 based on available information. If other sources are correct, the KIM-1 followed, then the Apple-1 and on from there. I'm wondering if anything might have come before that.

Thanks!!

Hi, unclefalter, and welcome!

Yes, it seems very likely a 6502 with a 3875 datecode will have the ROR bug. Here's an article about the bug, which investigates a chip with a later datecode and includes test programs:
https://www.pagetable.com/?p=406

I do like the OSI 300, for the minimalism and for the front panel!
We have this thread with further pointers:
viewtopic.php?f=3&t=3558
and see also Hans' page here:
http://retro.hansotten.nl/6502-sbc/osi-300-trainer/

The manual is here:
http://www.osiweb.org/manuals/OSI_300.pdf
and there's a video about it here:
https://www.youtube.com/watch?v=OTmFDruVQrY

I suspect you only need a few bytes of program to test one case of ROR A.

According to this page the JOLT came out slightly earlier than the KIM:
http://www.old-computers.com/museum/doc.asp?c=875
(JOLT in November '75)

Welcome!


Very likely:

https://www.pagetable.com/?p=406


The Jolt was very early too, but it's hard to say with any absolute certainty which can claim to have the first true "sale".

http://www.vintagecomputer.net/browse_thread.cfm?id=567
https://www.youtube.com/watch?v=TXMr-mB8C3o

(Did Ray Holt start designing the Jolt for the 6800 first? Because there shouldn't have been any 65xx samples in '74 ... maybe someone is "mis-remembering"?)



[Edit: Bah! BigEd trumped me by a few minutes ...]

_________________
Got a kilobyte lying fallow in your 65xx's memory map? Sprinkle some VTL02C on it and see how it grows on you!

Mike B. (about me) (learning how to github)

That's a good thought, about the 6800. I don't know if there was any pre-publicity about the possibility of the 6502 appearing. A product designed for the 6800 wouldn't need much modification - and the economics of the 6502 were a whole lot better.

Oh, sorry!

Ahhh I forgot about the Jolt! Thank you!!

I've been trying to nail down the origins of OSI and the 300 board but it is a bit murky. Different sources will say both OSI's founding and the 300 product happened in late 1975 or nearly 1976. The first ad reference I found for OSI and the 300 was in Byte, Feb 1976. But with the mention of the Superboard 600 in there I have a feeling the 300 had already been out for a while before then. The ad doesn't say 'introducing' or anything that suggests it was a new product.

I dug a bit deeper. [url]This link https://books.google.ca/books?id=iD4EAA ... =false/url] describes OSI as having started in 1975, and mentions the trainer (presumably the 300) being their first successful product, subsequently advertised in Byte, resulting in a flood of orders in Nov 1975.

I found Mike Cheiky online hoping to email and ask, but unfortunately he passed away in December 2017. Charity is still alive but I've not found a contact.

I did check the BYTE Nov 1975 issue but no ad. Thinking maybe it was in October?

But yeah.. if the article above is accurate and the Jolt was only offered in Dec 1975, the OSI 300 did beat it.

The first OSI ad I found in Byte is in the December 1975 issue and looks like the Superboard, not the 300:
https://archive.org/details/byte-magazi ... /page/n103

In those very early days it sounds like the first ads would have been in the electronics magazines - as mentioned by Ray Holt in the video Mike posted.

Also worth noting that magazines were usually published the month before the cover date, with the deadline for copy presumably being a few weeks earlier. So the date of the first sale could be 6-8 weeks adrift, if it was to someone local who heard about the product by word of mouth.

But notable that this advert sells the board for 6800, 6502 and 6501.

Yeah I'm thinking the article I cited above was referring to the 400 "Superboard" and not the 300. The 300 may have been the one they aimed unsuccessfully at the education market. Since we know the 400 was being advertised in/around late 1975, we can assume the 300, which was OSI's first product, preceded that. That would put it in contention for 'first' with the Jolt, assuming there wasn't something earlier, which there could well be.

Ah, yes, that makes sense. And it feels likely that the 300 would have been designed originally as a 6800 board. The launch of the much reduced cost 6501 and 6502 would have been a bit advantage. (I used a 6800 board, briefly, at Uni in the early 80s)