Search found 337 matches
- Mon Jul 04, 2022 1:38 pm
- Forum: Hardware
- Topic: Timex 2048 only 16k
- Replies: 49
- Views: 11368
Re: Timex 2048 only 16k
The latest and most accurate schematic of Timex Computer 2048, PCB rev 5 attached. Is this different to the version here ? Yes, It is. The version (1.3) in the linked tread had a few errors, that been corrected in the latest rev 1.8. I will zip the latest schematic and attach here when I am back ho...
- Sun Jul 03, 2022 6:40 pm
- Forum: Hardware
- Topic: RAMPACK and Hi-RES mod ?
- Replies: 23
- Views: 12884
Re: RAMPACK and Hi-RES mod ?
I have never mentioned about NAND gate for /RD and /RFSH. AND gate is needed, so 2 diodes and resistor can do the trick. This AND gate is essential for external RAM packs built with dynamic RAM chips.
- Sun Jul 03, 2022 6:34 pm
- Forum: Hardware
- Topic: Timex 2048 only 16k
- Replies: 49
- Views: 11368
Re: Timex 2048 only 16k
The latest and most accurate schematic of Timex Computer 2048, PCB rev 5 attached.
- Thu Nov 11, 2021 6:22 am
- Forum: Hardware
- Topic: Spectrum error
- Replies: 20
- Views: 7123
Re: Spectrum error
It might be speculation if M1 issues were related to any Z80 brand fitted in the factory. But M1 fault is only related to some Z80 made by Zilog in 80-ies. Nobody reported such issue with factory fitted NEC or SGS made CPU's. Not fully functional Z80'ies in ZX Spectrums might be a result of a cost s...
- Wed Nov 10, 2021 8:58 pm
- Forum: Hardware
- Topic: Spectrum error
- Replies: 20
- Views: 7123
Re: Spectrum error
M1 line is not used in ZX Spectrum. Many of ZX Spectrum left factory with faulty/non-active M1 line in the fitted Z80.
- Wed Nov 10, 2021 9:49 am
- Forum: Hardware
- Topic: 128K Toastrack Lower RAM Fail
- Replies: 12
- Views: 3876
Re: 128K Toastrack Lower RAM Fail
Yes, just corrected.
The data sheet attached.
The data sheet attached.
- Wed Nov 10, 2021 6:27 am
- Forum: Hardware
- Topic: 128K Toastrack Lower RAM Fail
- Replies: 12
- Views: 3876
Re: 128K Toastrack Lower RAM Fail
KM41464's are not good for Toastrack, because they are 4bit DRAMs and were used in +2A/B and +3.
For Toastracks and the upper RAM of any Spectrum 48K, suitable Samsung brand chips are KM4164B
For Toastracks and the upper RAM of any Spectrum 48K, suitable Samsung brand chips are KM4164B
- Sun Nov 07, 2021 8:14 am
- Forum: Z88
- Topic: Diagram for making your own cartridges?
- Replies: 15
- Views: 16598
Re: Diagram for making your own cartridges?
Wow! This is impressive.
One comment, the cartridge seems to be too wide and it would not fit into the slot.
There are no contacts on the other side because sockets are single sided. See photos.
One comment, the cartridge seems to be too wide and it would not fit into the slot.
There are no contacts on the other side because sockets are single sided. See photos.
- Tue Nov 02, 2021 6:21 am
- Forum: Z88
- Topic: Diagram for making your own cartridges?
- Replies: 15
- Views: 16598
Re: Diagram for making your own cartridges?
Hi, please see the attached.
- Fri Oct 08, 2021 9:09 am
- Forum: Hardware
- Topic: BT audio & wireless tape loading to ZX81
- Replies: 1
- Views: 1632
Re: BT audio & wireless tape loading to ZX81
The external BT module for ZX family, just tested with a ZX Spectrum clone. Have a look there: https://youtu.be/rLYKKHdo0hs
Tests with ZX81 and Jupiter ACE will follow soon.
Tests with ZX81 and Jupiter ACE will follow soon.