Denial

Ok, well, I built my cable last weekend, so I'll do some more reading and give this a try.

Building the connection cable is easy. 1. get a normal stereo audio cable (two lines plus the ground) and two connectors for the RS232 port. 2. Mark each connector with a label "TOP SIDE" just to avoid confusion later 3. Solder the ground of the cable to the A pin of both connectors. 4. C...

Thanks for the pointers, I managed to achieve what I wanted. Posting in case it helps anyone learning in future. ; process keyboard input of verbs or noun codes proc_input jsr t_clbuff ; clear kb buffer jsr clear_nv ; clear the current value from screen lda #0 sta TMP ; init our input count pi_plot ...

Hey chysm - you did and I have used it as a basis for what I'm doing. Many thanks.

Hey mike, Here's some pseudo pseudo code of what I am trying to achieve: When 'V' is pressed Loop: Move cursor to a specific column and row on screen Read a key Verify it is numeric If not numeric discard and jump to loop If numeric display the entered number at the cursor location Increment the cur...

Hey Mike, I'm not working on this very often, it's a hobby project I revisit on Fridays after work (you'll be be pleased to know I'm not a programmer :D ) When I have time. I don't have a BASIC version as I'm using this project to learn Assembly language. The responses from the others in the thread ...

ChatGPT, no way - I'm just learning and making mistakes, I don't need a machine to "do" that for me. :D "it doesn't work quite right" is not exactly helpful to describe what you might think is wrong with the routine. Ok, so I think I'm probably calling the wrong routines to get k...

Hi all, I'm still working on my Apollo DSKY on the 3k Vic 20 :D I'm trying to. Move the cursor to a specific row/col , get a 2 character input and check that it is made up of numbers. Here's my code - suffice to say it doesn't work quite right... verb_input jsr t_clbuff ; clear kb buffer lda #0 sta ...

Thanks Mike, I'll take a look at that. I'm emulating a peripheral, that's why I wanted to explore this approach.

Hi all, Could anyone recommend a good tutorial for interrupt handling on the Vic? What I want to do is regularly check a memory location and then update the screen based on what I find, then carry on with normal processing. At a later point I will be wanting to check for keyboard input and processin...

Thanks - it's working that way just fine, just trying to be efficient

So is there a short cut using the same EOR method to adding / subtracting 72? I have a char set with 144 characters, first 72 are normal video, final 72 are reversed and I need code to switch between them. I tried EOR and got the wrong answer. So I just wrote the longer version with adc/sbc. 24 EOR ...

Worked a treat and my routine is working primo Thanks for the help

Thanks Chysn, you're right that is really elegant, reusing the same pointer for both purposes.

Hi all, The following code snippet quoted from above: ; Set Character and Color ; Write character in A to screen memory specified by ZP pointer ; Set corresponding color memory to color Y ; (Unexpanded VIC) SetChCo: ldx #$00 sta (ZP,x) jsr flip tya sta (ZP,x) flip: lda ZP+1 eor #$88 sta ZP+1 rts Is ...