Search found 988 matches

by Paul
Sun Feb 10, 2019 12:40 pm
Forum: Hardware
Topic: ZX 128k +2 french " grey " : scart cable ...
Replies: 9
Views: 531

Re: ZX 128k +2 french " grey " : scart cable ...

In all computer where caps are required to generate voltages its necessary to exchange the caps. They dry out and the voltages generated don't fit anymore. The RAMs requiring these voltages will break. Therfore yes. All spectrum computers require new caps. In a ZX81 the caps are only in nonimportant...
by Paul
Thu Jan 31, 2019 12:47 pm
Forum: Hardware
Topic: "Mageco" disk controler. [infos, Docs wanted]
Replies: 45
Views: 3230

Re: "Mageco" disk controler. [infos, Docs wanted]

No. Dir on CP/M 2.x and before don't support subdirectories.
by Paul
Fri Jan 25, 2019 11:32 am
Forum: Hardware
Topic: Jupiter Ace - Case Dimensions
Replies: 17
Views: 658

Re: Jupiter Ace - Case Dimensions

1024MAK wrote:
Fri Jan 25, 2019 10:36 am
For the EPROM, I was actually thinking about using a one time programmable AT27C256R-70PU (cost £1.23 / $1.39).

Mark
I always use W27C512. EPROM Compatible flash. Costs less than 1€
10 pcs are 5,06€ free postage from China.
by Paul
Wed Jan 09, 2019 4:25 pm
Forum: Hardware
Topic: Best solution for expanding ram to 128k on a zx48k?
Replies: 17
Views: 1427

Re: Best solution for expanding ram to 128k on a zx48k?

Yes, they are soldered inside. Both solutions need the internal 32k RAM to be desoldered. This is not easy and no beginners task. The internal version (wich I prefer) also needs the 16k lower RAM to be desoldered. Getting rid of the DRAM and replace by SRAM makes the critical negative voltage genera...
by Paul
Wed Jan 09, 2019 3:52 pm
Forum: Hardware
Topic: Best solution for expanding ram to 128k on a zx48k?
Replies: 17
Views: 1427

Re: Best solution for expanding ram to 128k on a zx48k?

Can you please post a photo of YOUR pcb? We would like to see if your upper 32k are socketed or not.
by Paul
Wed Jan 09, 2019 12:02 pm
Forum: Hardware
Topic: Best solution for expanding ram to 128k on a zx48k?
Replies: 17
Views: 1427

Re: Best solution for expanding ram to 128k on a zx48k?

My programmer is a tl866
I use latest lattice settings without problems.
I am not sure whether I have a deviceID check disabled or if it's on defaults.
Kind regards Paul
by Paul
Wed Jan 09, 2019 6:09 am
Forum: Hardware
Topic: Best solution for expanding ram to 128k on a zx48k?
Replies: 17
Views: 1427

Re: Best solution for expanding ram to 128k on a zx48k?

In all cases, you will need some programmable logic device (or devices). In the past GAL chips were popular. But a lot of the hobby friendly chips have been discontinued. You can still get some from eBay, but with the usual risks of such a marketplace. Hi Mark, While this was true for several years...
by Paul
Tue Jan 08, 2019 6:50 pm
Forum: Hardware
Topic: Some questions about ZXPand+ serial port
Replies: 12
Views: 1266

Re: Some questions about ZXPand+ serial port

Please don't hit me...
Did you translate the character from zeddy to ASCII?
Or is this automatic in ZXPand+?
What happens if you send the same character multiple times?
Always the same result or differs the result periodically?
Kind regards Paul
by Paul
Tue Jan 08, 2019 7:51 am
Forum: Hardware
Topic: Some questions about ZXPand+ serial port
Replies: 12
Views: 1266

Re: Some questions about ZXPand+ serial port

mrtinb wrote:
Tue Jan 08, 2019 6:28 am

Hardware handshakes are not available on the ZX81, so we have to use software handshake (XON/XOFF).
This only applies to ZXPand. The ZX-TEAM serial port cards have full hardware handshake.
Kind regards Paul
by Paul
Tue Jan 08, 2019 6:06 am
Forum: Hardware
Topic: Some questions about ZXPand+ serial port
Replies: 12
Views: 1266

Re: Some questions about ZXPand+ serial port

I have no additional information about ZXPand+, sorry. There is also a serial port card from the German ZX-TEAM available, no ZXBasic commands available, just MC. Zeddynet requires RAM in the Area 0-8K only for initialisation. Once you are connected most of these bytes are not needed anymore. I can ...