Search found 739 matches

by siggi
Thu Oct 19, 2017 8:59 am
Forum: Hardware
Topic: ADDRESSING RAM AT 16K+
Replies: 11
Views: 164

Re: ADDRESSING RAM AT 16K+

If you look at this schematic (where some errors have been corrected, ignore the French video circuitry) which shows the edge-connector connection points (the X's in square boxes), it may help. http://fetrmartin.free.fr/ZX81/schema_ZX81_Fr.gif There is still an error in this schematic: At edge conn...
by siggi
Fri Oct 13, 2017 8:57 am
Forum: Development
Topic: Explain this behavior
Replies: 14
Views: 543

Re: Explain this behavior

Maybe Wilf's NOVA could be used for that? http://www.user.dccnet.com/wrigter/index_files/nova2005.htm The most powerful feature of this program is the ability to create new Video Display files located anywhere in memory. A variable number of character per line, a variable number of lines per screen ...
by siggi
Fri Oct 13, 2017 8:48 am
Forum: ZX BASIC
Topic: ZX81 SNAKE GAME
Replies: 16
Views: 304

Re: ZX81 SNAKE GAME

The main loop seems to start at line 200?

You could speed up your game, if you move all the stuff for initializing to the "end" (and put a GOSUB "end" at line 1).
If the main loop is next to the beginning of the program, a GOTO "mainloop" takes less time to search that line (200).

Regards
Siggi
by siggi
Tue Oct 10, 2017 12:03 pm
Forum: SALES
Topic: Memopak 64K
Replies: 2
Views: 127

Re: Memopak 64K

GOTO ../SALES

;)
by siggi
Tue Oct 10, 2017 11:35 am
Forum: Hardware
Topic: Memotech Memopak 32k
Replies: 11
Views: 279

Re: Memotech Memopak 32k

I have no idea what I would do with 64k on a zeddy anyway! Or use ZXPAINT do draw (and print) some nice HIRES pictures: has its HIRES image at 8K-16K and needs ram above 32K to keep a second HIRES picture available: http://www.sinclairzxworld.com/viewtopic.php?f=6&t=260&p=1924&hilit=ZxPaint#p1910 S...
by siggi
Tue Oct 10, 2017 11:08 am
Forum: Hardware
Topic: Memotech Memopak 32k
Replies: 11
Views: 279

Re: Memotech Memopak 32k

I have a lot of ideas: run ZeddyNet and its applications: - use ram at 8-16K for ZeddyNet system variables - run ZeddyFox or NFM (network filemanager) in ram 32K-48K - load/save a BASIC-Program (using ZeddyFox or NFM) in ram 16-32K Or use IRC-ANSI.P (ZX81 chat program) at 16-32K, having its ZeddyNet...
by siggi
Tue Oct 10, 2017 9:34 am
Forum: Hardware
Topic: Memotech Memopak 32k
Replies: 11
Views: 279

Re: Memotech Memopak 32k

Lots of nice little spaces ready for additional chips to maybe make it up to 64K? The board itself may probably also be used for 64K ram modules. But AFAIK the Memotech rams contain a programmed chip (PROM?) for address decoding. So you would need to get the appropriate PROM for the 64K board.... S...
by siggi
Tue Oct 10, 2017 8:34 am
Forum: Development
Topic: Solved: Calling MAKE-ROOM/099E
Replies: 11
Views: 219

Re: Solved: Calling MAKE-ROOM/099E

I've made a small program that start with RAND USR 16515 10 REM CODE 5[3]RND[' ][: ] LN [2]{..}TAN **** 4083 219F40 LD HL,409F 4086 010500 LD BC,0005 4089 CD9E09 CALL 099E 408C C9 RET 408D 17 "*" 408E 17 "*" 408F 17 "*" 4090 17 "*" 20 LET A$="AA" I assumed my program would insert 5 spaces in line 2...
by siggi
Tue Oct 10, 2017 8:01 am
Forum: Hardware
Topic: Memotech Memopak 32k
Replies: 11
Views: 279

Re: Memotech Memopak 32k

In this old thread you will find a lot of information (and pics) of Memotech modules (incl. ram):

viewtopic.php?f=7&t=865&p=8583&hilit=memotech+ram#p8583

Regards
Siggi
by siggi
Mon Oct 09, 2017 9:06 pm
Forum: Development
Topic: Solved: Calling MAKE-ROOM/099E
Replies: 11
Views: 219

Re: Calling MAKE-ROOM/099E

It is NOT a good idea to run this routine during SLOW mode. If you insert bytes into a program line, not only the line length will no more fit, but the DFILE is also moved upwards. This could result in a crahs, when the display is generated while the DFILE is moved or before the system variables (po...