Search found 2779 matches

by sirmorris
Fri Feb 23, 2018 3:21 pm
Forum: Hardware
Topic: Memotech HRG: ROM mirroring!
Replies: 14
Views: 288

Re: Memotech HRG: ROM mirroring!

The Memotech hardware presumably does something like this: when you write to addresses 0000-0fff enable RAM, disable ROM when you read from addresses 0000-0fff and I register is even, disable RAM, enable the ROM when you read from addresses 0000-0fff and I register is odd, enable RAM, disable ROM Un...
by sirmorris
Thu Feb 22, 2018 3:09 pm
Forum: Hardware
Topic: Memotech HRG: ROM mirroring!
Replies: 14
Views: 288

Re: Memotech HRG: ROM mirroring!

Hmm the second.

Wilf has analysed the board and produced some hints. I think there is a button which needs to be pressed to toggle the RAM/ROM overlaying. I also think that some initialisation of the HRG is necessary before things work as expected.
by sirmorris
Thu Feb 22, 2018 2:37 pm
Forum: Hardware
Topic: Memotech HRG: ROM mirroring!
Replies: 14
Views: 288

Re: Memotech HRG: ROM mirroring!

Hmm. // Memotech Hi-res board has 1k of RAM available at address 8192 // permanently and overlaid the ROM at address 0 when z80.i is odd // or data is written to address 0-1k if (Address<=zx81.ROMTOP && zx81.protectROM) { if ((zx81.truehires==HIRESMEMOTECH) && (Address<1024)) memhrg[Address]=Data; r...
by sirmorris
Wed Feb 21, 2018 9:31 pm
Forum: Hardware
Topic: Problem with my new ZXpand+
Replies: 20
Views: 516

Re: Problem with my new ZXpand+

:roll:
by sirmorris
Wed Feb 21, 2018 7:07 pm
Forum: Welcome Area
Topic: Welcome to the SINCLAIR ZX WORLD forums
Replies: 9
Views: 257

Re: Welcome to the SINCLAIR ZX WORLD forums

msch wrote:
Wed Feb 21, 2018 11:32 am
Look at the first post from 2008:
viewtopic.php?p=2
It had to be me with the first reply hahaha..!
by sirmorris
Tue Feb 20, 2018 11:39 pm
Forum: Welcome Area
Topic: Welcome to the SINCLAIR ZX WORLD forums
Replies: 9
Views: 257

Re: Welcome to the SINCLAIR ZX WORLD forums

Welcome home guys!
by sirmorris
Mon Feb 19, 2018 10:11 am
Forum: Hardware
Topic: Problem with my new ZXpand+
Replies: 20
Views: 516

Re: Problem with my new ZXpand+

Please start a new topic in Development to discuss the serial transfer. That way the information will be easier to find for others wanting the same thing. Also I'm not sure what you mean - 'Receiving data from the zx81' implies that the zeddy will be sending to some other device - is that the case? ...
by sirmorris
Sun Feb 18, 2018 5:19 pm
Forum: Development
Topic: Plot function in z88dk
Replies: 28
Views: 1056

Re: Plot function in z88dk

OH ALL RIGHT ALL RIGHT so games _do_ PLOT :P :lol:
by sirmorris
Sat Feb 17, 2018 10:29 pm
Forum: Development
Topic: Plot function in z88dk
Replies: 28
Views: 1056

Re: Plot function in z88dk

Games don't PLOT. Just sayin' ;)
by sirmorris
Sat Feb 17, 2018 8:46 am
Forum: Hardware
Topic: Problem with my new ZXpand+
Replies: 20
Views: 516

Re: Problem with my new ZXpand+

+1 for cleaning edge connector. And wiggling the ZXpand in-place with the power off. There is a slim possibility that the CPLD has become corrupted. Do a CPLD re-flash too using the second part of the instructions posted earlier and THIS file. The process takes 3-4 minutes, and it might look like no...