Smonson's slow H4 build

[kodak80]

@Smonson I have purchase from this seller a few times and components have worked fine.

They also sell them in 5 packs: https://www.ebay.com.au/itm/5pcs-HN27C4 ... 2103004850

[exxos]

I never cease to be amazed that you can buy 32GB of flash for $10 and yet a chip with less than a meg on it can be the same price or more.

Try buying 100 of them each time like I have to :lol: :roll:

[Smonson]

Try buying 100 of them each time like I have to :lol: :roll:

Ummm, I might pass... :lol:

[PaulJ]

Thanks @PaulJ. Gosh they're not cheap for a OTP, are they :shock:

Ya you're right but I have good reason for buying quality OTP. Initially with the Remake board I purchased 4 of the EEPROM Kodak80 listed. I did this because I was putting together the images for the OTP chips and I didn't want to be able erase and reprogram. The first failed in about 10 minutes.. stone cold dead, the remained 3 appeared to be running fine. When I built my 1.04/DiagROM I could not get the DiagROM half to run no matter what I did. Tried a second EEPROM.. same shit. Put them in the eprom programmer and would tell me I had the programmed image. Finally out of despiration I tried the third and last EEPROM. It worked!!!! SAME IMAGE! I had wasted days playing with eBay cut rate crap. So from that point on I made sure to get quality prom devices. I still use the EEPROMS but if they don't work I don't take that as a bad image. At that time @Phil was having the same issue. So if it fails to work don't assume you have a bad image.

So I wasted about 20 hours of effort and a lot of head scratching.. its worth a few bucks to me to avoid massive loss of time and dealing with a issue that makes no sense.

[kodak80]

I had issues programming the OTP chips and I binned 6 chips through programming fails. I switched to the UV erasable ones and also had programming issues which turned out to be a worn ZIF socket on my programmer.

I have found on my new programmer that the UV chips need to be held in the adapter to ensure all pins are connected and programming works 9 times out of 10 but even if it fails I can erase them and try again. I have not yet had one that I could not program.

[PaulJ]

I had issues programming the OTP chips and I binned 6 chips through programming fails. I switched to the UV erasable ones and also had programming issues which turned out to be a worn ZIF socket on my programmer.

I have found on my new programmer that the UV chips need to be held in the adapter to ensure all pins are connected and programming works 9 times out of 10 but even if it fails I can erase them and try again. I have not yet had one that I could not program.

Ya, when making a new image I use the erasable and after it works burn a OTP. I've trashed a few of the OTP's when I think I couldn't screw it up.. but do.

[Smonson]

Got most of the passives on now, and I've got a SIMM socket coming. I started depopulating my donor board. The first thing I ran into was the reversed reset switch footprint. I don't really want to bend the switch to make it fit - I might just drill a couple of extra holes for the shield. Has anyone else done this successfully?

[exxos]

Don't drill holes, you risk shorting out the internal power planes.

[Smonson]

Hmm, okay, I won't be doing that then!

[exxos]

Derkom said it just went on a bit wonky https://www.exxosforum.co.uk/forum/viewt ... =40#p29128