Hi How's everyone doing??

I.ve been buying the parts to proceed on this .. I ordered a western design 816S and 6522 to work with, I'm going to put the 816S & 6522 on the vending board and move the 65c02 from the vending board to replace the NMOS chip in the Microbot board..

I installed 6 Pololu ...

To make it match the Microbot board require 8 traces be changed, Which is my goal with this thing.. How much room is there for ram at the bottom before you hit I/O addressing.. Or haven't you got that far with the code yet..

6821 PIA only has two register addresses lines instead of 4 on the 6522 or 6822 and has 2 IRQ outputs instead of one .. And a couple pins are are in different positions.. It would require cutting 8 traces to the socket and jumping them to the right signals.. There are no functional problems with ...

Tony .. To my disappointment .. They are PIA's not VIA's HD468B21P..
Lee has them listed in the dis-assembly as VIA's which needs to be corrected..

Anyway to make the board compatible with the Microbot code I either have to build a daughter board with a VIA, Or cut 8 traces on the board and jumper ...

Thanks Lee ... That PAL makes it impossible to figure out the memory map with a multimeter and truth tables... I imagine its not quite as interesting to disassemble as the robot code was.. Best I can figure it had a bill changer and some kind of alpha numeric display.. I think the 24C02 serial flash ...

Got the Star MFG Board, It's a Vending machine board, It has is a R65C02P2 2 mhz, Uses PAL 16L8 address decoder, 32k Eprom 2k Ram and Two 68B21 PIA's, I/O Two PIA's and four buss drivers and one transciever .. 14 OC outputs,, Two 74LS138 Decode Addressing for off board locations

l VALUE CARD SHOP ...

Handy PCB reference... Haven't designed to many PCB's in my life (mostly wire wrap or point to point vector-board), But repaired several thousand that smoked... But once my PCB CNC is finished I'll be using them for ref...

You only get two design methodologies .. Overkill, Or do the math... Its a ...

Sorry I had allot of driver datasheets open, And was comparing them, I must have been looking at the wrong datasheet when I quoted 400ma,, The 2803's are only capable of 175ma all drivers on..

But anyways you have to remember the collectors are the output pins and also where the heat goes.. To run ...

Tony .. I know when you designed it you had a use in mind and it wasn't pumping out 48 amps, So don't take my observation to seriously..

The circuit is nice and versatile.. Only things I would change on the layout is to put the TIP120's next to the output pins, Or move the output pins inboard next ...

Tony .. Yea I'd like to scope out the schematic..

Got the Ultratech board already, And it is not quite what it appeared to be.. It in fact has tip122's not 127's, Each emitter has two 2w 16 ohm resistors in parallel equaling 8 ohms to ground which charges a 220uf 50v cap also on the emitter ...

Tony .. Nice versatile driver board, I will keep it in mind, But suffer's the problem I'm trying to get away from, Using NPN driver transistors with the ULN2803's or any open collector pre-driver requires they be turned on to turn off the tip122's.. It seems you solved that by putting the 74HCT595's ...

Lee ... That's the same ebay store I bought mine from .. But at a better price, Seems this board comes from a laser CNC machine, Because one of the other boards from ultratech is listed as a 5 axis laser focus board..

Tony ... I heard Williams arcade uses allot of 6502's in their boards.. Do you ...

Hey I got it wright for a change ... My guess is the reason a CR stops prior execution would be so a stop command is processed immediately..

Did you see the drive board I bought, 24 tip127 darlingtons.. I uploaded a few low res pics of it..

I bought some more parts for my PCB CNC today, It will ...

Glad you got a good laugh from it ...

I digress slightly, But years ago when they had the New York power blackout.. The Tech that found the problem was asked what he charged the city for fixing the problem, Which had been a relay with welded contacts... His answer was " 1$ for tapping, And a $1000 for knowing where to tap..