Search found 453 matches

by Martin A
08 Mar 2020 15:08
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 53
Views: 7793

Re: Another Home-Brew - Z180

If you have a "spare" EPM7128, you could shove that into the CFX-II and test your USB blaster with that. And hopefully confirm that it is working.
by Martin A
11 Feb 2020 00:03
Forum: OFF TOPIC
Topic: PCBs for Spectrum Clones
Replies: 17
Views: 1599

Re: PCBs for Spectrum Clones

So, is anyone else ready to take up the challenge ?
by Martin A
09 Feb 2020 18:27
Forum: OFF TOPIC
Topic: PCBs for Spectrum Clones
Replies: 17
Views: 1599

Re: PCBs for Spectrum Clones

It's built, I had nothing better to do while sheltering inside from storm Ciara, so I've finished the Harlequin 128 build. Here's the board with everything except the rom added just the rom to add.jpg Now with the rom fitted and the keyboard mounted completed.jpg The 512k flash has room for 8 differ...
by Martin A
08 Feb 2020 23:50
Forum: OFF TOPIC
Topic: PCBs for Spectrum Clones
Replies: 17
Views: 1599

Re: PCBs for Spectrum Clones

I think (I hope!) that's all the soldering done, I'll do some basic tests tomorrow and then start populating the ICs.
all soldering done I hope.jpg
all soldering done I hope.jpg (145.97 KiB) Viewed 745 times
by Martin A
08 Feb 2020 23:47
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 53
Views: 7793

Re: Another Home-Brew - Z180

Using PVC insulated wire is a LOT trickier than using the Kynar covered "stuff" designed for wire wrapping.

PVC tends to shrink back when a hot iron is placed on the wire, Kynar doesn't, that makes a massive difference when you've got a few hundred, (or thousand) points to wire.
by Martin A
07 Feb 2020 00:21
Forum: OFF TOPIC
Topic: PCBs for Spectrum Clones
Replies: 17
Views: 1599

Re: PCBs for Spectrum Clones

The package from the Mouser in the US arrived today, so no I can add more than just empty sockets to the board. The bits have arrived.jpg I fitted the AD724 first, getting to those pins once the surrounding parts are fixed would be awkward in the extreme. I then fitted all the other sockets and star...
by Martin A
04 Feb 2020 21:13
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 53
Views: 7793

Re: Another Home-Brew - Z180

I don't know if this is any help for testing: https://hackaday.com/2015/10/28/programmable-logic-build-yourself-a-cpld-module/#more-174019 Bill Herd (of Commodore fame) put together a CPLD breadboard module for the 44 pin Max. It could be that the master programmer also does something with voltage l...
by Martin A
02 Feb 2020 14:11
Forum: OFF TOPIC
Topic: Another Home-Brew - Z180
Replies: 53
Views: 7793

Re: Another Home-Brew - Z180

I had issues in the past with my "USB blaster" (it's a clone) failing to program that were basically down to the cheap USB lead that came with it not fitting properly. Once I switched to a higher quality lead the problems went away.
by Martin A
01 Feb 2020 14:49
Forum: OFF TOPIC
Topic: PCBs for Spectrum Clones
Replies: 17
Views: 1599

Re: PCBs for Spectrum Clones

Nothing slow enough to sync to the Spectrum's RGB output except the TV via SCART, and 8 pin mini din to SCART isn't exactly common... (I will fit the mini din socket just in case.) Composite on the other hand I've a range of displays from the 30+ year old V7001 to a 4" reversing camera screen. Fitti...
by Martin A
01 Feb 2020 12:16
Forum: OFF TOPIC
Topic: PCBs for Spectrum Clones
Replies: 17
Views: 1599

Re: PCBs for Spectrum Clones

So, I took Bill up on the offer of a Spectrum clone PCB. I know he want's some updates, so I've posted a couple of pictures. :D While I wait for the rest of the parts to arrive in post from the US, I've started on the keyboard. I used the 48k spectrum as a guide, since there's no way to duplicate th...