Search found 1331 matches

by srowe
Sat Dec 09, 2023 1:58 am
Forum: General Topics
Topic: Bugs & Quirks in the VIC-20 BASIC & KERNAL ROMs
Replies: 4
Views: 2792

Re: Bugs & Quirks in the VIC-20 BASIC & KERNAL ROMs

I was just working with the keyboard decode tables this morning, and I was wondering about the purpose of this whole page of NOPs. And not necessarily a bug, but they’re not being very elegant about setting the decode table index, either. I've recently disassembled the VIC-1001 ROM in this area, I'...
by srowe
Fri Dec 08, 2023 3:32 pm
Forum: General Topics
Topic: Bugs & Quirks in the VIC-20 BASIC & KERNAL ROMs
Replies: 4
Views: 2792

Bugs & Quirks in the VIC-20 BASIC & KERNAL ROMs

The firmware in the VIC-20 is a remarkable feat of engineering (given the primitive development and debugging tools available at the time it was written). While compared to some other computers of the era it is relatively bug-free there are a number of issues present. BASIC VERIFY Result When the VE...
by srowe
Sat Dec 02, 2023 1:21 pm
Forum: Programming
Topic: Help needed for "Frames Per Second Counter / Monitor"
Replies: 5
Views: 2638

Re: Help needed for "Frames Per Second Counter / Monitor"

My question is, is this interrupt routine correct? Can the jump to the $EABF routine be implemented differently? That depends on what you want happen during an interrupt. The KERNAL routine is this https://eden.mose.org.uk/gitweb/?p=rom-reverse.git;a=blob;f=src/basic_kernal.asm;hb=HEAD#l10602 it's ...
by srowe
Sun Nov 26, 2023 2:29 am
Forum: Programming
Topic: "Ultimate Expansion" - new firmware for FE3
Replies: 59
Views: 9929

Re: "Ultimate Expansion" - new firmware for FE3

A new release (1.7) with another new feature. I've added a Minipaint image slideshow viewer to the "FE3 Utilities" menu (F5). Each file is displayed in turn, key press/joystick moves to the next image. Press [STOP] to exit.
by srowe
Tue Nov 21, 2023 1:21 pm
Forum: Emulation and Cross Development
Topic: Vic20 code editors / IDE for Mac
Replies: 5
Views: 3164

Re: Vic20 code editors / IDE for Mac

chysn wrote: Tue Nov 21, 2023 9:49 am
I automate most non-coding tasks with shell scripts. For converting BASIC text to tokenized BASIC, like Mike said, use petcat.
You can also do this with cbm-shell

Code: Select all

cbm-shell "unlist example.txt example.prg" quit
by srowe
Mon Nov 20, 2023 2:22 pm
Forum: Hardware and Tech
Topic: User Port PCB?
Replies: 3
Views: 2523

Re: User Port PCB?

Not quite the same but I found this

https://www.ebay.com/itm/314765290463
by srowe
Wed Nov 15, 2023 2:50 pm
Forum: Collecting and History
Topic: De-yellowing your VIC-20 case
Replies: 47
Views: 17812

Re: De-yellowing your VIC-20 case

Wayne / Art Ravers wrote: Wed Nov 15, 2023 2:24 pm I have already acquired a Kernal Rom Chip, just need to get a 6502 now - Any suggestions on Places that are reliable please ?
I'm pretty sure I've ordered parts from this guy

https://www.ebay.co.uk/itm/325396424917
by srowe
Sat Oct 28, 2023 2:55 am
Forum: Hardware and Tech
Topic: 6560 Maximum Memory
Replies: 7
Views: 2523

Re: 6560 Maximum Memory

DrVeryEvil wrote: Wed Oct 25, 2023 2:38 pm A quick tip, all the data and address line are accessible from the character ROM chip. :D
Back in the 80's I made an internal 3K expansion module that fitted into the socket

https://www.sleepingelephant.com/ipw-we ... php?t=7016
by srowe
Thu Oct 26, 2023 10:35 am
Forum: Programming
Topic: "Ultimate Expansion" - new firmware for FE3
Replies: 59
Views: 9929

Re: "Ultimate Expansion" - new firmware for FE3

I've updated the user guide I wrote to include all the new features

https://eden.mose.org.uk/download/FE3%2 ... 0Guide.pdf
by srowe
Thu Oct 26, 2023 4:46 am
Forum: Programming
Topic: File Command Errors
Replies: 31
Views: 6111

Re: File Command Errors

chysn wrote: Sun Oct 22, 2023 9:55 am I'm not sure which SD2IEC I have. It doesn't really say anything on it except for "sd2iec". When I run the command "X?" it returns
Read the command channel immediately after boot, it returns the firmware version.
by srowe
Mon Oct 23, 2023 12:50 am
Forum: Programming
Topic: "Ultimate Expansion" - new firmware for FE3
Replies: 59
Views: 9929

Re: "Ultimate Expansion" - new firmware for FE3

A new release (1.6) with another new feature. I've added a simple directory/image navigator (F2 from the main menu). This allows you to easily traverse a directory tree on the SD card, including entering images, and then boot to BASIC without needing loader files. Download link: https://eden.mose.or...
by srowe
Thu Oct 19, 2023 1:29 am
Forum: Games
Topic: Mega Vault by Imagine .PRG file
Replies: 9
Views: 3085

Re: Mega Vault by Imagine .PRG file

I don't think it's possible to create a single .PRG file for this game. It contains several files that all load to the same address (except the last one) (cbm) file 0:* LOADER (SYS850): PRG, size=69 bytes, start=$0352 STAGE1: PRG, size=4098 bytes, start=$1000 STAGE2: PRG, size=1026 bytes, start=$100...
by srowe
Wed Oct 18, 2023 1:01 pm
Forum: General Topics
Topic: VIC-1001 main board
Replies: 9
Views: 2883

Re: VIC-1001 main board

Mayhem wrote: Tue Oct 17, 2023 3:22 pm I think what's more surprising is there are PAL Vic20 from Japan. They are all in the 5xxxxx serial number range I believe.
The one I have has a 5xxxxx serial number.
by srowe
Mon Oct 09, 2023 5:47 am
Forum: General Topics
Topic: VIC-1001 main board
Replies: 9
Views: 2883

Re: VIC-1001 main board

Could you attach a photo?
by srowe
Thu Oct 05, 2023 1:21 am
Forum: Programming
Topic: Assembly: Detect when result rolls over from 255 to 0
Replies: 6
Views: 2211

Re: Assembly: Detect when result rolls over from 255 to 0

When adding to the accumulator using ADC, how can I detect whether a zero roll-over has taken place? That's precisely what the carry bit is for, so your original code should have been bcc inc_src_hi_ptr_done There are a number of implementations of block moves in the 6502.org code repository, http:...