Search found 395 matches
- 26 Mar 2020 10:06
- Forum: BASIC
- Topic: SDX High Memory
- Replies: 10
- Views: 12480
Re: SDX High Memory
Agree, not all the BDOS is required for the SDX, but it is an interesting compromise: The simplest solution would have been to load the BDOS/BIOS in full, and place the file control blocks and other data structures below that. This would however use the maximum amount of high memory. Putting these d...
- 24 Mar 2020 18:26
- Forum: BASIC
- Topic: SDX High Memory
- Replies: 10
- Views: 12480
SDX High Memory
I have been trying to improve my understanding of exactly what use SDX BASIC makes of high memory (above 0xC000). The first thing I found is that only part of high memory is initialised when you first start the system. A lot more is loaded into high memory when you issue a USER command. To investiga...
- 21 Mar 2020 18:00
- Forum: OFF TOPIC
- Topic: Another Home-Brew - Z180
- Replies: 102
- Views: 109024
Re: Another Home-Brew - Z180
Finally found the first issue with my USB Blaster clone. The ten wire data cable had been assembled with one of the connectors reversed :o I did not have a spare connector, and these IDC connectors are not meant to be removable. However, with some careful levering I was eventually able to remove the...
- 07 Mar 2020 22:14
- Forum: OFF TOPIC
- Topic: Another Home-Brew - Z180
- Replies: 102
- Views: 109024
Re: Another Home-Brew - Z180
I have not had much free time to work on this recently, but I am making slow progress. At least I now know that my EPM7032S chips are not JTAG locked :) Altera developed the Jam Standard Test and Programming Language for defining the signals needed to program and test JTAG devices. The idea is that ...
- 17 Feb 2020 19:20
- Forum: OFF TOPIC
- Topic: PCBs for Spectrum Clones
- Replies: 17
- Views: 22532
Re: PCBs for Spectrum Clones
A couple more PCBs have arrived from Lez: Another ZX Spectrum Clone: SuperFo Harlequin Rev 6. A much smaller board: RC6502 Apple 1 Replica, Revision F (pictured). Lez suggested Martin should have first refusal on this one. Apple_1.png I also still have from the first batch: ZX Max 48 - This one uses...
- 10 Feb 2020 11:33
- Forum: OFF TOPIC
- Topic: PCBs for Spectrum Clones
- Replies: 17
- Views: 22532
Re: PCBs for Spectrum Clones
I knew it would not take you long
Lez will be pleased that at least one of the boards he supplied has been put to use.
Lez will be pleased that at least one of the boards he supplied has been put to use.
- 08 Feb 2020 15:33
- Forum: OFF TOPIC
- Topic: Another Home-Brew - Z180
- Replies: 102
- Views: 109024
Re: Another Home-Brew - Z180
20200208_131107.jpg 20200208_131043.jpg My boards for testing 7032 CPLD and USB Blaster on a breadboard. Now need to investigate whether I can program any of the chips. One advantage of having made these is that I can also test the logic of the programmed CPLD independent of the main circuit. Makin...
- 03 Feb 2020 10:18
- Forum: OFF TOPIC
- Topic: Another Home-Brew - Z180
- Replies: 102
- Views: 109024
Re: Another Home-Brew - Z180
Dave, Many thanks for the offer. However I am using the smaller 7032S in my design. I have five of these chips from Lez, so hopefully at least a couple should be usable, even assuming that this is the problem. If not I will have to buy some more. I have also been wondering how the master programmer ...
- 02 Feb 2020 20:07
- Forum: OFF TOPIC
- Topic: Another Home-Brew - Z180
- Replies: 102
- Views: 109024
Re: Another Home-Brew - Z180
Dave, That issue had occurred to me, and is a possibility. I am not sure there was an error message, other than "Failed", when attempting to program. When I did the JTAG test, I got the "No device found" message. I don't remember exact messages, and don't have the system in front...
- 02 Feb 2020 15:19
- Forum: OFF TOPIC
- Topic: Another Home-Brew - Z180
- Replies: 102
- Views: 109024
Re: Another Home-Brew - Z180
Martin,
Thanks for the suggestion. It may be that, but I don't think so. The lead seems to be good quality and a good fit. Also there is activity on the programmer LED when attempting to program.
Experimentation is required.
Thanks for the suggestion. It may be that, but I don't think so. The lead seems to be good quality and a good fit. Also there is activity on the programmer LED when attempting to program.
Experimentation is required.