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California 1702A EPROM programming/dumping by mail service - EPROM Hut

Covers: California
bzotto

bzotto

Experienced Member
Joined
Jan 25, 2022
Messages
112
Location
San Francisco, USA
Hey folks-- through some of my own projects, I've ended up with equipment that can dump and program the elusive 1702/1702A EPROMs as well as 2704/2708/2716 etc. I know this need comes up occasionally in the 1970s computing stuff, and not everyone wants to DIY or scavenge a programmer. Since I have the equipment around anyway I decided to hang a web shingle to offer the world's most incredibly niche hobbyist service to other vintage computing people. If you need to work with 1702As (etc) and I can be of assistance let me know, here's the page!
eprom-hut.com

EPROM Hut - Obsolete EPROM Services For Today's Vintage Aficionado

Programming and Reading Services for Vintage and Obsolete EPROM chips: Intel 1702A, 2704, 2708, 2716, more!
eprom-hut.com
 
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Welcome to VCFED.

This looks to be a handy adventure - not that I have a requirement at the moment though.

Can I suggest adding your location to your profile though? I guess you are in the States somewhere (as your prices are in dollars).

Dave
 
daver2 said:
Can I suggest adding your location to your profile though? I guess you are in the States somewhere (as your prices are in dollars).
Click to expand...
Done, thanks Dave. I am indeed in the States-- I'm more than happy to help out anyone outside the US, but the US international outbound postage has gotten almost prohibitively expensive so it may or may not make sense. Anyway, hope this will be useful for someone at some point.
 
Hi
I'm always looking for code used by the Intel SIM4 setups. I'm looking for the A0542 EPROM that has the correct timing for the 1702 ( non-A ) EPROMs. I'm also looking for the ROM set A0750-A0758 ( The ROM simulator ). If you find 1702A with these labels please don't erase them.
I do have A0540,A0541 and A0543. I also have the assembler, A0740-A0743.
I have a setup to program 1702As but it is flaky right now and I've not had time to analyze the failure.
I have a large box of 1702As that were pulls. Most with bent or broken pins. If anyone needs a few 1702As for a project let me know. If 4 or 5, I'll send them for shipping cost. If the pins are broken, they can be easily piggy backed by soldering a pin from a sacrificed chip.
I don't have any white Intel chips in the box( nothing collectible ). These are mostly second source vendors but do have a few Intel purple packages.
Dwight
 
sometime in february I should have this chip: DEC 23-640A2. it's on the board at ebay listing 225783908740. the chip is "256 x 4 16-pin, eg 82S129, MMI630." replacement parts include: amd 27S11 or 29761, signetics N-82S129, TI SN-74S287, harris hm-7611-5, intel 3621, intersil 5623, rayethon 29661, or of course MMI-6301-1. the chip is marked : (Signetics) 88339 DM74S287N N82S129N / L8420 640A2 ; board markings include: 5415482 5015481C1P1 Side 1/2 L1-L4 (must be four layers) PC100 RX50 controller. I want it dumped. I find bzotto mentioned at a page "some EPROM programming services" at minuszerodegrees. I might try to do it myself, should I find my roll of solder. can you help, bzotto?
 
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I only see one of these chips on the board at the auction listing so I'm guessing it's used as a lookup map of some kind by the disk controller for GCR or something-- because it's only 4 bits wide you'd generally need at least two to store byte-sized data. Unfortunately I don't have ready hardware to dump PROMs like this, and I don't see it listed on the Xgecu device support list that you'd be able to get cheapishly from amazon. But from the datasheet I'm looking at this design seems straightforward enough-- if you have a breadboard and an Arduino handy, it's a pretty manageable little project-- tie the enables to ground, iterate through the address lines as your output, and capture the four data out signals as your input. It only needs a +5V supply.

I believe this part is also, funnily enough, the same chip (as MMI6301) that Apple 1 replica builders use; there may be a go-to device those folks know about to work with these chips which could also dump them for you (maybe ask elsewhere here or on Applefritter?).

Anyway, feel free to drop me a PM (or an email at the site above) if you really get stuck. Good luck!
 
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