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Mar 25, 2021
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New Zealand
Despite very well informed advice to the contrary; I've gone straight to the bottom of the market and bought the xgecu t48 (sometimes advertised as TL866II+ G3) as the cheapest eprom programmer that has a greater-than-zero chance of working for my use case

xgecu made a number of highly questionable design decisions on the t48 to hit a price point, and one of those decisions was to put the ZIF socket in upside down. I'm guessing that they couldn't route the traces and didn't want to pay extra for more layers.
What this means its that the 42 pin adapter for 27c160/322/400/800 from this awesome project
does in theory still work, but in practise it's very difficult to mount the adapter on the device because the top of the adapter blocks the (stupidly placed) ZIF lever.

There is also an ongoing annoyance with the adapter that the DIP switch bank is incorrectly marked on the silk-screen, this is actually fixed in the most recent release. Its easy enough to invert the switch bank, but then the silkscreen shows 0 and 1 conflicting with the markings on the switch

Luckily the CADs are published as part of the repo here

Cut a notch out to make room for the zif lever on the t48
Screen Shot 2024-02-23 at 8.51.59 PM.png

Did a quick fix of the silkscreen. The DIP switch bank still needs to go on backwards, but now the silkscreen is backwards too so everything matches
Screen Shot 2024-02-23 at 8.52.08 PM.png

Have not tested this, will post the CADs/gerbers when I've tested it and know that it works - if anyone has a burning desire to have them right now drop me a message and I'll send em.
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Sometimes its easy to fall in love with my own project, but for $4 including delivery your solution is so much better.

The ability to write in a single pass is definitely the "killer feature" here.

Thank you very much for pointing this out, have ordered now

I would have preferred to create a new fiber for the original adapter.. (sorry)
I like these projects and I don't want them to disappear..

Your adjustments to the flood adapter are great.
I also have the adapter and it is good when you need, for example, to upload the same file (512kb) multiple times to one chip.


The attachment is great (saves time)
Set directly, for example: Type 27c322
It sets the correct voltages, checks the ID of the chip and uploads it directly, without splitting the file and checks the upload.
No need to simulate (27C4096).
For example, I found out that I have two fakes (27C322), it said bad ID
And they were (27V322).
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If the adapter works I'll probably re-draw it for CAD practise and leave room for a 48 pin ZIF socket. Or if I get bored (which is likely) I might just chop 6 of the legs off one of the 48 pin sockets I've got laying around.

Stay tuned for pictures of dubious modifications!
Did you ever try the plain 42 pin adapter without ISP? I'd like to make the adapter work by cutting off some of the PCB, but I don't understand how to adjust the programming routine to ignore the missing ISP connection

Edit: the obvious answer is to simply not use the writing procedure of the T48 (which is specialised for 27C322) and instead use the one for AM27C4096... Apparently reading comprehension is not my strength.
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