arkleyjoe

Defender Galaxian Pac Man Millsile Command Space Invaders Star Raiders Asteroids Pole Position Tennis ET Phone Home Soccer Shamus GATO Miner 2049er Barnyard Blaster Can send more photos if required. I'd like to sell the collection as a whole. Open to sensible offers. I am UK based.

Hi, I wonder if anyone can help. I have a faulty Virtual Boy and it needs a replacement mirror servo board. Does anyone have one they could spare and would like to sell or maybe a faulty VB I can use for spares?

Hi, I wonder if anyone can help. I have a faulty Virtual Boy and it needs a replacement mirror servo board. Does anyone have one they could spare and would like to sell or maybe a faulty VB I can use for spares?

So some progress. I have removed and socketed the 74LS logic chips near the battery. I do not have replacements on hand, have ordered them today. However if I remove u13 the 74LS373 the halt line comes up and I see activity on the other lines. So my hope is that when I replace this it will be ok, or alternatively it will be a problem with the ram.

I would like to buy a virtual boy servo board as I have a faulty one on which the mirrors do not sync. If anyone has one they could spare I'd like to buy it

@Daedalus2097, I am pretty sure there is no brief period where it is high. I see nothing more than a tiny flicker on the line but more like low level interference rather than activity by design. here are the are some behaviours of the halt line in different scenarios. 1) gary / cpu in place = halt low. 2) gary out / cpu in = halt low. 3) gary out / cpu out = halt high. 4) gary in / cpu out = halt high. So I think this rules out a short on the halt line between Gary and CPU?? But both chips are known good. So as @Daedalus2097.suggested previously maybe the CPU is halting because it finds a fault elsewhere?

Reference: try to boot with Gary removed and the Halt line stays constantly low, then the CPU is potentially the issue. If I boot with Gary removed the HALT stays low. However halt also stays low in my known good machine with Gary removed.

Hey, I have since managed to remove the agnus and I have replaced the socket with a new better quality one.

Hey, IIRC lol I have been scanning schematics for that This one is turning in to a real puzzle. So I did have some broken traces around that resistor pack near Gary and I have repaired and thoroughly tested again all of the traces right though to their final destination. Gary, CPU and ROM have been tested in a known good machine. I get close as damn it 4.7k ohms between halt and ground / 5v. That resistor pack did have a little corrosion around it but I suppose if I am getting 4.7k ohms on Halt it is functioning correctly? I have also reflowed the CPU socket just incase there is an issue there and still no joy

Hi Daedalus2097, thank you very much for your help. Sorry for the slow reply. So in reply to your specific points: You don't even get a very short burst of bus activity, no?: No nothing at all that I can see. I would check the ROM socket, including the alignment (the ROM socket should have an empty row at the pin 1 end. : Rom socket and alignment it in seems fine. Tested the rom in another machine, all good. What is the halt line doing? My halt line is stuck low. Not even a twitch. Continuity is fine between Gary and the CPU on the halt line. What is the IIRC?? I am pretty sure if I can work out the cause of the low halt line it will point to my cause. Any tips on causes of that? My Diagrom does nothing but I guess that it is not even attempting to read that?

Perfect I will get in touch thank you.

Hi, I have a couple of faulty A500+ Rev 8A boards both with battery damage. One is a total mess the other had 2 /3 broken traces which I have fixed, but I need some advice as what to try next. What I have done so far: On both boards, I have tested and fixed any continuity issues, focussing on the usual area around Gary, Replaced Gary's socket. replaced the 74LS244 in U12 Swap tested all of the ICs with known good chips / board. Tested clocks / power. So this is the current state of play with each board. Board 1 (the lightly damaged board): I get black screen and the power light stays dim. There is a sync signal to the monitor albeit no pic. I have tested with a diagrom. No difference still black screen. I have scoped around and there does not seem to be any activity on the address lines. Reset lines on CPU / Gary seem to behave normally low for a moment and then stays high. I am not sure what to try next on board 1? Additionally, Agnus is welded in to its socket on this board. Later I plan to replace the socket with a better one but can not get it out. For now I plan to leave it alone unless it is likely / potentially part of the fault? Board 2 (the horrendous board that now has so many botch wires it looks like a breadboard project : This board amazingly is getting to a green screen which I know indicates a ram problem. I tried piggy backing the ram but this did not change anything. My question here is simply I am not sure if I should start desoldering the ram OR is it more likely to be the other 74 logic chips near the damage? Joe

I had a similar problem with my screen and it turned out I had attached D0 and D1 to the wrong pins on the Lynx. They were both 1 pin off where they should have been. I would check the wires and pins are all correct.

Hi I have just upgraded an old lynx 2 with a McWill LCD. That has worked out fine. However every time I reassemble the lynx a different selection of the buttons on the front are not working. I wonder if my ribbon cable is knackered. It is possible to get replacements? Or is there else going on maybe? Joe

Hi, Please add me to your pre order list.

Perfect thank you for your help.

Hi, I have a 2600 jnr which is only showing black and white display. I have opened it up and the pot that controls the colour is badly c so i suspect that is the problem. However I do not know what to replace it with. Can anyone help me work out the correct replacement part? Much appreciated. Joe

Stargunner thank you very much. TBH i did not think it was possible to get a direct replacement any longer. I will order the ones you have suggested. Thanks again. Joe

Hi, I am looking to replace the audio capacitors in my Atari 2600. The existing ones are 820pf Polystyrene and I am trying to find a direct replacement I can order from RS or Mouser here in the UK. Can anyone give me a some guidance on what I can use to replace them? I have been told I can use 820pf MLCC but do not know any more about the specs / datasheet in order to decide which to order. Any help is greatly appreciated. Alternatively does anyone in the UK do these kits like console5? https://console5.com/store/atari-2600-total-refresh-kit-new-capacitors.html The postage to the UK just makes ordering from those guys way too expensive. Joe

Ahh good call I will take a look.

BTW to add further I am really referring to the lines of code around line 86 of the ASM file.

Hi I now have a piece of code that is scrolling as I want. (attached) My approach to getting the scrolling is to have a counter that increments / decrements each frame and I use that o push the PF along. Could anyone let me know if this is the right basic approach? I appreciate the code is a mess right now, I just want to know I have the basic concept in place before I continue. Your input is greatly appreciated. pftest.asm

Hey, thank you for coming back so quickly. Hugely appreciated. Ok that was REALLY helpful. Using that technique, I realised that I was falling through my subroutines rather than jumping strait to Overscan once I had reached the 192 lines. This meant that I was adding a few additional scan lines. Thanks for pointing me in the right direction and thanks for the additional hint on the way I was attempting to address the play field pattern values. That has cleared up something else that was confusing me. Now I have it stable I would like to understand how to make it scroll again in a controlled way. If you could help me understand how to approach the scrolling I would really appreciate it. I have attached the fixed pftest.asm Many thanks Joe pftest.asm

Hi This is a bit of a strange question. I am attempting to make a vertical scrolling play field and I have managed to get something very similar to what I need but I am not 100% sure how I have done it. In my code below I can not work out why the play field is scrolling. I would expect it to be static, the same in every frame based on my current understanding. Can anyone tell me why this is rolling and point me in the direction as to how I may control the speed of this scrolling. Maybe I have miss understood the cycle count and so I am on multiple scan lines? I do see a little glitch in the debugger. Here is my sample code: processor 6502 include "vcs.h" include "macro.h" PATTERN1 = #%00110000 PATTERN2 = #%01111000 StartCount = 0 CURRPF = 1 SEG ORG $F000 Reset ldx #0 lda #0 Clear sta 0,x inx bne Clear ;one time set up lda CURRPF ;set up the PF to mirror sta CTRLPF ;set up the PF to mirror ldy StartCount ; set to 0 lda PATTERN1 ;load part one of the patern. sta PF0 ;load part one of the patern. lda #$55 ;set the colour sta COLUPF ; set the colour StartOfFrame lda #0 ;2 sta VBLANK ;3 lda #2 ;2 sta VSYNC ;3 sta WSYNC ;3 sta WSYNC ;3 sta WSYNC ;3 ldx #0 ;2 VerticalBlank sta WSYNC ;3 inx ;2 cpx #37 ;3 bne VerticalBlank ;3 Picture sta WSYNC ;3 3 cpy #20 ;3 8 bcc ShowPathern2 ;2 10 lda PATTERN1 ;3 13 sta PF0 ;3 16 cpy #40 ;3 19 beq ResetPFDraw ;2 21 iny inx ;2 23 cpx #192 ;2 25 bne Picture ;2 26 sta VBLANK ;3 29 ldx #0 ;2 31 ldy #0 ;2 33 ShowPathern2 iny lda PATTERN2 ;3 3 sta PF0 ;3 6 inx ;3 9 cpx #192 ;2 11 bne Picture ;2 13 sta VBLANK ;3 ldx #0 ;2 ldy #0 ;2 ResetPFDraw ldy StartCount ;3 3 inx ;2 5 nop ;2 7 cpx #192 ;2 9 bne Picture ;2 12 sta VBLANK ;3 ldx #0 ;2 ldy #0 ;2 Overscan sta WSYNC inx cpx #30 bne Overscan jmp StartOfFrame ORG $FFFA InterruptVectors .word Reset .word Reset .word Reset END I have attached the bin file also. pftest.asm.bin

This should be quite simple. You can add another variable where you currently have have y=50 add a new variable. For example: i=0 : rem Used to count collisions. where you test for collision in this line. if collision(player1,player0) then COLUBK=$28 else COLUBK=200 You should adjust that line to increment your counter. if collision(player1,player0) then i=i+1 That would be a simple way to do it. I hope that points you in the right direction. Joe