Search found 914 matches

by siggi
Sat Aug 29, 2020 12:26 pm
Forum: Hardware
Topic: RAM keeps failing
Replies: 9
Views: 584

Re: RAM keeps failing

There might be a timing problem, which occurs using modern and fast ram chips. See there: https://www.sinclairzxworld.com/viewtopic.php?p=2620#p2620 " The problem is the old design of the ZX80/81, where the internal RAM's output drivers are enabled together with the complete chip ( /CE conneted to /...
by siggi
Thu Jun 11, 2020 7:53 pm
Forum: Development
Topic: ZX81 interrupts with z88dk, how to install an ISR ?
Replies: 19
Views: 3378

Re: ZX81 interrupts with z88dk, how to install an ISR ?

FYI: old feature request for Z88DK about this topic: https://www.z88dk.org/forum/viewtopic.php?id=4877 old thread about this topic: https://www.sinclairzxworld.com/viewtopic.php?p=31046#p31046 BTW: in my ZX81-MIDI-Player I am using the ZX81 NMI interrupt generator to make the MIDI clock. Of course t...
by siggi
Thu Jun 11, 2020 1:20 pm
Forum: Development
Topic: ZX81 interrupts with z88dk, how to install an ISR ?
Replies: 19
Views: 3378

Re: ZX81 interrupts with z88dk, how to install an ISR ?

Using BASIC and machine code, Wilf's NOVA allows to call "short" or "long" machine code routines during display. Docs are here (switch to character set "western" for correct display). http://www.user.dccnet.com/wrigter/index_files/nova2005.htm Siggi PS: The "machine code" could also be a compiled C ...
by siggi
Thu Jun 11, 2020 10:46 am
Forum: Development
Topic: ZX81 interrupts with z88dk, how to install an ISR ?
Replies: 19
Views: 3378

Re: ZX81 interrupts with z88dk, how to install an ISR ?

Let me explain. By using IM2 and having no device to put the right byte you may jump to anywhere in a page because it will read a fake byte on the data bus. The ZX81 has 10K pullup resistors connected to the data bus. Thus if no device drives the data bus during interrupt acknowledge cycle, the Z80...
by siggi
Sun May 17, 2020 6:06 pm
Forum: Hardware
Topic: Zx81 (Ts1000) case technical drawings
Replies: 36
Views: 3717

Re: Zx81 (Ts1000) case technical drawings

Yes, the size seems to be the same. Distance between the "Europa hole" and the visible frame of the American hole is 13 mm, the distance to the EAR hole is 6 mm.
Siggi
by siggi
Sun May 17, 2020 4:24 pm
Forum: Hardware
Topic: Zx81 (Ts1000) case technical drawings
Replies: 36
Views: 3717

Re: Zx81 (Ts1000) case technical drawings

The position of the American version TV socket is a little bit visible at the European case version (see pic).
So maybe the European socket is also visible on the Amercian case?

Siggi
by siggi
Sun May 17, 2020 8:56 am
Forum: Hardware
Topic: Zx81 (Ts1000) case technical drawings
Replies: 36
Views: 3717

Re: Zx81 (Ts1000) case technical drawings

There are 2 variants of the the case for 2 different locations of the TV connector: in Europe the connector is closer the the MIC/EAR/POWER sockets than in America:
IMG_6335_800x600.JPG
by siggi
Thu Apr 09, 2020 11:24 pm
Forum: Development
Topic: Pseudo HR prototype
Replies: 11
Views: 3011

Re: Pseudo HR prototype

Hi Stefano this is a picture on a good LCD colour monitor, generated by a ZX81NU (no ULA), having a BIGBANG-ROM. The pixels seem to be identical, so maybe the rom region, which is used as "character generator" by your program, is not modified compared to the original Sinclair rom. The picture ist st...
by siggi
Mon Mar 30, 2020 5:03 pm
Forum: Development
Topic: Midiplayer, using a DUART and a LCD
Replies: 21
Views: 3453

Re: Midiplayer, using a DUART and a LCD

Meanwhile Joachim has updated the software of the LCD display: now it supports also German special characters (e. g. used by Nena ;) )
And I have modified the midiplayer for better readability of the Karaoke text:

IMG_6254_1024x768.JPG
by siggi
Sat Mar 28, 2020 3:19 pm
Forum: Development
Topic: Midiplayer, using a DUART and a LCD
Replies: 21
Views: 3453

Re: Midiplayer, using a DUART and a LCD

Did you think about confessing a voice synthesizer to sing? Indeed: https://forum.tlienhard.com/phpBB3/viewtopic.php?p=42838#p42838 :mrgreen: But that would require a conversion of text into vocals at realtime (between 2 MIDI-events) AND an AI to detect the language ... :mrgreen: @Moggy: here it is...