Search found 324 matches

by jpnz
Wed Jan 31, 2024 9:12 am
Forum: Announcements
Topic: Master your ZX Microdrive - Second Edition
Replies: 2
Views: 372

Master your ZX Microdrive - Second Edition

There was a second edition of Master your ZX Microdrive book that "details the differences between the three types of Interface 1"... https://twitter.com/warmtoffee/status/1302178881361924096 After two failed attempts to get hold of the second edition, the third time has indeed been the ch...
by jpnz
Sun Jan 28, 2024 8:32 am
Forum: Games/Software
Topic: Guess the screen$
Replies: 7898
Views: 239083

Re: Guess the screen$

Time for a clue? The author is quite prolific and this isn’t their first game…
by jpnz
Sat Jan 27, 2024 6:04 am
Forum: Games/Software
Topic: Guess the screen$
Replies: 7898
Views: 239083

Re: Guess the screen$

None of those, sorry - so some more details

Image
by jpnz
Sat Jan 27, 2024 3:44 am
Forum: Website
Topic: PDF manuals
Replies: 23
Views: 1833

Re: PDF manuals

It seems that this error was introduced when the author initially ocr'ed and fixed the manual - see http://hayne.net/Spectrum/HiSoftBASIC/ The easy confirmation is to write a basic program with the inverse keyword and see if it does indeed compile to code 120. On a side note, the lack of alternativ...
by jpnz
Fri Jan 26, 2024 9:48 am
Forum: Games/Software
Topic: Guess the screen$
Replies: 7898
Views: 239083

Re: Guess the screen$

Great, let's have a go with this

Image
by jpnz
Thu Jan 25, 2024 10:29 pm
Forum: Games/Software
Topic: Guess the screen$
Replies: 7898
Views: 239083

Re: Guess the screen$

bluespikey wrote: Thu Jan 25, 2024 8:17 pm Image
Manic Miner
by jpnz
Mon Jan 22, 2024 9:45 am
Forum: Programming
Topic: How much self modifying code was there and did it do anything?
Replies: 26
Views: 1410

Re: How much self modifying code was there and did it do anything?

Self modifying code is great It can be used to make "things" relocatable - i.e load some code into memory exactly (within reason) where you want it to run and execution will " fixup " itself A good example is HiSoft Devpac GENS & MONS A 1981 relocation article from a TRS-80 c...
by jpnz
Wed Jan 17, 2024 9:48 am
Forum: Games/Software
Topic: Guess the screen$
Replies: 7898
Views: 239083

Re: Guess the screen$

Dalek Attack / Sylvester McCoy

Take another go, I've got nothing to put up
by jpnz
Wed Jan 03, 2024 6:52 pm
Forum: Programming
Topic: Games with real time played?
Replies: 15
Views: 691

Re: Games with real time played?

Impossible Mission - 6 hours to complete the task at hand
by jpnz
Sun Dec 31, 2023 11:00 am
Forum: Announcements
Topic: Happy New Year!
Replies: 24
Views: 977

Happy New Year!

From the Southern hemisphere, raising a glass and toasting you all - a Happy New Year!

by jpnz
Fri Dec 29, 2023 11:23 pm
Forum: Hardware
Topic: Serial port madness
Replies: 1
Views: 180

Serial port madness

I've posted before about the Interface One transmitting at non-standard baud rates under emulation

Seems like the real hardware will actually do it as well...



Insane!
by jpnz
Mon Dec 25, 2023 8:12 am
Forum: Music
Topic: We Wish You a Merry Christmas
Replies: 31
Views: 1462

Re: We Wish You a Merry Christmas

Merry Christmas folks, have a superb day!

by jpnz
Thu Dec 14, 2023 6:11 am
Forum: Sinclair Miscellaneous
Topic: The mother of all chopping boards
Replies: 8
Views: 560

The mother of all chopping boards

I've no idea who ordered this, but it turned up in the office kitchen a few weeks back...
Spoiler
Image

Image
Pretty cool!
by jpnz
Thu Oct 19, 2023 10:48 am
Forum: Emulators
Topic: Any emulators able to pause on completon of loading?
Replies: 31
Views: 866

Re: Any emulators able to pause on completon of loading?

Just a thought... activating the IF1 will bump out the system variables by 58 bytes Loading a file from the microdrive will also consume some further 595 bytes Once the file is loaded, those 595 bytes should be released But those extra system variables will still persist Maybe consider collapsing th...
by jpnz
Thu Oct 19, 2023 7:00 am
Forum: Programming
Topic: Erasing multiple copies of a file on a microdrive
Replies: 1
Views: 142

Re: Erasing multiple copies of a file on a microdrive

Machine code version: ; ; [ba]star[d] ERASE - oct 2023 ; erase multiple copies ; of file on microdrive ; proof of concept - no error handling ; mailto:jp@drumfu.com ; org &8000 ; d_str1 equ &5cd6 ; 2 byte drive number 1 - 8 l_str1 equ &5cd9 ; device type "m", "n", &qu...
by jpnz
Wed Oct 18, 2023 11:14 am
Forum: Programming
Topic: Erasing multiple copies of a file on a microdrive
Replies: 1
Views: 142

Erasing multiple copies of a file on a microdrive

The subject of speeding up microdrive load times with multiple copies of a file was mentioned a couple of weeks back: You can speed up the seek times by having more than one copy on the cart and this technique applies to other files as well The system variable 0x5cef (COPIES) supports this, e.g to s...
by jpnz
Tue Oct 17, 2023 12:49 am
Forum: Emulators
Topic: Any emulators able to pause on completon of loading?
Replies: 31
Views: 866

Re: Any emulators able to pause on completon of loading?

For ROM based loaders a break point at 0x0555 is a good spot The break point triggers on completion of loading either a header or code, so loading something like Manic Miner would trigger 6 times Ideally take your snapshot while the 6th trigger is in place Restarting execution would then traverse it...
by jpnz
Sun Oct 01, 2023 5:17 am
Forum: Hardware
Topic: Yet another Microdrive emulator...
Replies: 81
Views: 7038

Re: Yet another Microdrive emulator...

I found a collection of Game MDRs online and the speed at which most load, seems almost as quick as a DIVMMC device once the BASIC "run" file is located on the virtual tape. You can speed up the seek times by having more than one copy on the cart and this technique applies to other files ...
by jpnz
Thu Sep 28, 2023 8:19 am
Forum: Sales/Commercial
Topic: WTB: Fruitcake ZXC4 cartridge
Replies: 2
Views: 182

Re: WTB: Fruitcake ZXC4 cartridge

If you can get hold of a ZXC4 cartridge then you'll need a serial cable to really make the most of it The cables, like the cartridges, look to be sold out as well but the pin out is detailed here - you could make your own if you're handy like that I can't help with ZXC4 carts, but as an alternative ...
by jpnz
Thu Sep 28, 2023 8:03 am
Forum: Games/Software
Topic: The Speccy Arcade 100 - 2023 Edition
Replies: 1
Views: 159

The Speccy Arcade 100 - 2023 Edition

Sharing a post from the other forum by Rev_Stuart_Campbell Updated from the 2021 original, with new entries and reshuffles a-go-go, and now all in one gigantic feature: http://wosland.podgamer.com/the-speccy-arcade-100-2023-edition/ You might want to give it a moment or two to finish loading before ...
by jpnz
Sat Sep 16, 2023 9:50 am
Forum: Hardware
Topic: Detect which Microdrive a program is running from?
Replies: 5
Views: 238

Re: Detect which Microdrive a program is running from?

8BitSC wrote: Sat Sep 16, 2023 1:41 am Thank you @jpnz

Googling for an answer before posting here, I found many results. None made it seem quite this simple.
Hope it works out for you - for reference, this was originally published in Master Your ZX Microdrive, page 21 - Chaining programs

The whole book is a good read
by jpnz
Fri Sep 15, 2023 9:04 am
Forum: Hardware
Topic: Detect which Microdrive a program is running from?
Replies: 5
Views: 238

Re: Detect which Microdrive a program is running from?

Yes, you can use the system variable D_STR1 (drive number), e.g.

Code: Select all

LET d=PEEK 23766: LOAD *"m";d;"somefile"
by jpnz
Thu Sep 14, 2023 11:16 am
Forum: Hardware
Topic: Odd Kempston Interface 'Plus'
Replies: 5
Views: 303

Re: Odd Kempston Interface 'Plus'

1024MAK wrote: Tue Sep 12, 2023 5:14 pm Not sure if those yellow thinks are extra buttons, they do look like they may be.
Mark
I'm curious as to what they may do - any thoughts?

I had fitted a button in an IF2 to force a reset, but stopped short at a second one for triggering an NMI given the logic in the stock ROM
by jpnz
Sat Sep 09, 2023 11:05 am
Forum: Preservation
Topic: SSTV
Replies: 2
Views: 184

Re: SSTV

This version of G1FTU SSTV was prepared for call sign G4FVW Converting the "SSTV Sample Pictures (Pearsons Computing) - Side 1" WAV to Unsigned 8-bit PCM, and RX into SSTV (via Spectaculator) results in this: https://youtu.be/VPIoIiMzJ7E This is ~13 minutes long, but you'll get the gist af...