Search found 1819 matches

by 1024MAK
Mon Jan 08, 2018 4:41 pm
Forum: Hardware
Topic: Improving Timex/Sinclair Tape Loading
Replies: 70
Views: 3088

Re: Improving Timex/Sinclair Tape Loading

Diodes (and LEDs):-
Image
Image

Mark
by 1024MAK
Sat Jan 06, 2018 6:08 pm
Forum: Hardware
Topic: TS1000's (ZX81's) black screen
Replies: 10
Views: 250

Re: TS1000's (ZX81's) black screen

PokeMon wrote:
Sat Jan 06, 2018 6:00 pm
You can order them quite cheap from Aliexpress:

https://de.aliexpress.com/item/100-teil ... 82982.html

100 pieces with 12 cent each - no shipment fee.
Thanks :D

Mark
by 1024MAK
Sat Jan 06, 2018 2:22 pm
Forum: Hardware
Topic: TS1000's (ZX81's) black screen
Replies: 10
Views: 250

Re: TS1000's (ZX81's) black screen

Good that you have found a supplier of MPS2369 transistors. When I looked a couple of months ago, I could not find any that were in stock apart from on eBay.

Mark
by 1024MAK
Fri Jan 05, 2018 11:38 pm
Forum: Hardware
Topic: TS1000's (ZX81's) black screen
Replies: 10
Views: 250

Re: TS1000's (ZX81's) black screen

The only source of ZTX313 or MPS2369 transistors appears to be eBay...

Mark
by 1024MAK
Tue Jan 02, 2018 8:09 pm
Forum: Development
Topic: ZXMore development thread
Replies: 7
Views: 164

Re: ZXMore development thread

Oh yeah :D

Mark
by 1024MAK
Tue Jan 02, 2018 1:09 am
Forum: Hardware
Topic: Spectrum+ 128k repair help (No CPU clock signal from working ULA)
Replies: 6
Views: 126

Re: Spectrum+ 128k repair help (No CPU clock signal from working ULA)

When a 16k or 48k ZX Spectrum is reset or powered on, one of the first things that the code in the Sinclair BASIC ROM does is to set the border white. It then does a memory check ( not a full memory test) to see how much RAM is fitted. During this test, values are written to all the 48k RAM area, th...
by 1024MAK
Mon Jan 01, 2018 12:58 am
Forum: Hardware
Topic: Chroma 81 - SCART and Colour interface for the ZX81
Replies: 133
Views: 8402

Re: Chroma 81 - SCART and Colour interface for the ZX81

Yes, the current value of D_FILE is stored in the system variables area (two bytes at 16396), because D_FILE moves around in memory. It moves whenever the BASIC program length changes.

See chapter 27 and 28 in the ZX81 BASIC Programming manual.

Mark
by 1024MAK
Mon Jan 01, 2018 12:50 am
Forum: Sinclair Misc
Topic: Happy New Year
Replies: 5
Views: 164

Re: Happy New Year

Roll-up! Roll-up! Welcome to a brand new year! Boy, will we have a show for you! For our old time friend, Zeddy of Sinclair will continue it's amazing compute and display light fantastic for it's thirty-eighth year! Don't hold back, come now, right to the front, you don't want to miss even a minute!...
by 1024MAK
Sun Dec 31, 2017 9:21 pm
Forum: Hardware
Topic: Spectrum+ 128k repair help (No CPU clock signal from working ULA)
Replies: 6
Views: 126

Re: Spectrum+ 128k repair help (No CPU clock signal from working ULA)

Any ROM / EPROM / EEPROM / flash based RAM tester will work, but you need either an expansion device that has EPROM / EEPROM / flash memory, or be able to burn a EPROM / EEPROM / flash chip and put it in place of the machines ROM chip. See this site ;-) Note that the diagnostics boards are currently...
by 1024MAK
Sun Dec 31, 2017 6:50 pm
Forum: Hardware
Topic: My first wire wrap: Wilf's AT keyboard interface
Replies: 5
Views: 207

Re: My first wire wrap: Wilf's AT keyboard interface

Yeah, there are lots of advantages to wire wrap. However, one painful thing is if you have to remove(unwrap) a wire on the "bottom" of a pin due to a mistake/error/change of mind after wrapping one or more other wires further along the pin... :( And when properly constructed, a wire wrap board can h...