Search found 2953 matches

by Mike
Fri Sep 08, 2006 5:44 am
Forum: Programming
Topic: How to Move memory
Replies: 10
Views: 3490

Re: How to Move memory

How to move more then 256 bytes? In that case you must preface the copy routine to put the pointers to source and target into the corresponding ZP addresses: 1400 A9 00 LDA #lo_byte of source 1402 85 FB STA $FB 1404 A9 00 LDA #lo_byte of target 1406 85 FD STA $FD 1408 A9 20 LDA #hi_byte of source 1...
by Mike
Fri Sep 08, 2006 2:37 am
Forum: Programming
Topic: Over Writing Memory
Replies: 2
Views: 1302

Hi, Devlin, did you read my reply here?

Otherwise I don't understand why you are concerned about the remnants of the first program. No program should depend on contents of memory locations it has never touched before.

Michael
by Mike
Fri Sep 08, 2006 2:28 am
Forum: Programming
Topic: How to Move memory
Replies: 10
Views: 3490

How about: LDX #$4A loop LDA $1B4F,X STA $1C6F,X DEX BNE loop with fixed addresses and at most 256 bytes to copy, there's no need to use the full-fledged implementation with indirect addressing. The begin of source and target have been decremented by 1, since X counts down from 74 to 1, and the loop...
by Mike
Wed Sep 06, 2006 11:22 am
Forum: Hardware and Tech
Topic: a BASIC game as cartridge
Replies: 20
Views: 4439

Since the original program was designed to run in the unexpanded VIC, I really didn't think about running it from ROM. For bigger programs however, your ideas are a big improvement! The copy routine can be omitted entirely, and the ML section that sets the start of variables is replaced by a write t...
by Mike
Tue Sep 05, 2006 4:14 am
Forum: Hardware and Tech
Topic: The mystery of HD floppies resolved ?
Replies: 6
Views: 2513

Last year we discussed this within the topic ' DD vs. HD 5.25" Disks for a 1541 '. Especially I used the picture of a row of water buckets. I also wrote there (emphasis added): even reading a HD disc written as DD in a HD drive can cause problems in a DD drive, as DD heads can't handle the high...
by Mike
Wed Aug 30, 2006 1:57 pm
Forum: Hardware and Tech
Topic: a BASIC game as cartridge
Replies: 20
Views: 4439

a BASIC game as cartridge

These days I delved into hardware hacking. :) With Schema's method I successfully converted one of my games ( TRON Light Cycles ) into cartridge format. I had a leftover Personal Finance cartridge handy, onto which I crossed the lines A11 and A12, and then replaced the ROM chip with a programmed 273...
by Mike
Fri Aug 18, 2006 1:05 am
Forum: Programming
Topic: Games which use Multicolor characters
Replies: 22
Views: 4706

many TVs and of course monitors can be adjusted in height and width. [...] This gives room for a number of weird pixel ratios [...] When viewing a normal signal on a TV, I expect a circle to be a circle. That provided the TV won't be able to tell, that a VIC is delivering the signal (o.k. its signa...
by Mike
Wed Aug 16, 2006 12:50 am
Forum: Programming
Topic: Games which use Multicolor characters
Replies: 22
Views: 4706

the fact that modern PC's have uneven X to Y resolution. A real VIC has a much squarer screen the shape of a TV or monitor. ??? At least my TFT here has perfect square pixels. My PAL VIC has a pixel aspect ratio of 1.67:1 on a normal TV set (AV input). That said, the writers of VICE chose the appea...
by Mike
Tue Aug 08, 2006 1:28 am
Forum: Programming
Topic: Random Numbers
Replies: 16
Views: 4714

RND()

RND() is indeed some form of linear congruential generator. However, CBM tried to "improve" upon that, and made additional byteswaps onto the intermediate result. See here . This more or less breaks the generator. Since the number stored internally is 32 bits, we could hope, that the RND() only repe...
by Mike
Mon Aug 07, 2006 7:53 am
Forum: General Topics
Topic: Problems with PM
Replies: 10
Views: 6200

Tried to send you a Test-PM, and it seems I do have the same problem.

Michael
by Mike
Fri Aug 04, 2006 4:12 am
Forum: Programming
Topic: Making compute's gazette VIC turbodisk for ROM
Replies: 18
Views: 3830

I downloaded the Jul. '85 version of Turbodisk at arnold.c64.org, and made a quick shot at it. Turbodisk resides in the last 5 pages of the available RAM. The very last page is used as sector buffer. So the whole code only needs 1K, but ... 1. The filename is copied into the code, that is transferre...
by Mike
Fri Aug 04, 2006 1:12 am
Forum: Programming
Topic: Hires Graphics
Replies: 111
Views: 46546

I was wondering how the bitmap is arranged so I looked here and there: Bitmap and chars start both at 1000. Yep. With double-height characters, one needs 17 Bytes (1 text byte, 16 bitmap bytes) to display an 8x16 pixel cell. I didn't want to use the bottom 1K, so the calculation was: 4096/17 ~= 240...
by Mike
Wed Aug 02, 2006 8:08 am
Forum: General Topics
Topic: How to crunch basic programs
Replies: 1
Views: 2193

perform RUN from ML

You need to perform the following calls: JSR $C533 ;re-link BASIC program JSR $C659 ;reset TXTPTR JMP $C7AE ;handle next BASIC statement See here . If you have a fixed start of the BASIC program, you can omit the first JSR. Then you can embed this ML code (sans re-link) into your BASIC program as fo...
by Mike
Mon Jul 31, 2006 6:30 am
Forum: Programming
Topic: Hires Graphics
Replies: 111
Views: 46546

3D Bar Chart

Here's another application for MINIGRAFIK. A 3D Bar Chart. No more need to use E**el for this. ;) I was lucky to see the design allows for 12 bars over the screen width. So the program can accommodate the display of the fuel consumption of your car over the year, or similar things. Greetings, Michae...
by Mike
Mon Jul 31, 2006 6:16 am
Forum: Emulation and Cross Development
Topic: Help needed with VICE (Linux)
Replies: 10
Views: 7316

Hi, Thomas!

Code: Select all

xvic -memory none filename.prg

from the command line should do the trick.

Michael

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