Dennis Ferrons 6502 board...

Bamse

Howdy...

I'm trying to re-create the 6502 board that Dennis Ferron made for the Prop design contest...
www.parallax.com/tabid/708/Default.aspx

I thought I got it correct but the board just doesn't work...
The Demo Block Transfer just shows $00 on all addresses and 256 errors.
The Debug demo shows the 6502 address all over the place, kind of random.

The Lower 74HC244 is wired to the Low Byte addresses,
Pin 2 to address A0, 4-A1, 6-A2, 8-A3, 17-A4, 15-A5, 13-A6 and 11-A7.
Pin 18 to Propeller P0 over 1Kohm, 16-P1, 14-P2, 12-P3, 3-P4, 5-P5, 7-P6 and 9-P7.
Did I get this combination right ?
Upper 74HC244 is the same but with A8 to A15.

I could not find the SRAM in the project but I was able to get a free sample of DS1245AB-70.
www.maxim-ic.com/quick_view2.cfm/qv_pk/2664
It's wired according to the schematics, but A16 is pulled to ground.

I didn't have a 6502 so I used a WDC65C02.
www.westerndesigncenter.com/wdc/w65c02s-chip.cfm
Pin 36 (Bus Enable) is pulled high to +5V and Pin 1 (Vector Pull) is left floating since it's an output.

Besides that I've triple checked all the connections etc...
Just wonder if there is something obvious I forgot.

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

Bamse

FYI:
Realized that the HC series might not work, switched to 74LS244 and added a few NOPs in the program to slow things down...
I got the debugger to work, however the Block Transfer demo still do not work...

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

Baggers

keep up the good work Bamse, sorry I can't give any say on the matter, as I don't have any of the parts other than a prop [noparse]:D[/noparse] lol

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http://www.propgfx.co.uk/forum/·home of the PropGFX Lite

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Bamse

Thanks Baggers...

I was looking up the specs for the DS1245 and found out that this chip is $40.
Not really practical since I'm thinking of making a PCB for this.

I have a couple of 62256 (32Kb chips for $3 each) and I want to replace the DS1245 with two of these in stead.
So I'm going to piggy back two of those in the existing socket and use a 74LS04 (NOT gate) to "decode" A15 for Chip Enable.

That will be tonights exercise...

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

Bamse

Success...

Seems like the 62256 works a lot better, both debugger and block transfer works...
However there are some errors on memory location $B000 and above, I think I burned part of one of the RAM chips...

Time to tear things apart and put two memory chips side by side...

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

Cluso99

I note that the DS1245 is 128Kx8 and has internal battery backup. Your pair of 62256 should be fast enough and the 74LS04 should be fine to invert the address line, although it will slow access time this should not be a problem. Alternately, you could get a 128Kx8 SRAM AS6C1008 5V equivalent from Future Electronics (I bought a 512Kx8 AS6C4008 for about $3) - the pinout will work, just tie the pins 1 & 2 (check the chip spec) - make sure it will handle 5V.

I would have thought the 74HC244 would have been fine. Are you sure you are using +5V on the 6502 section.

What clock speed is the prop outputting to the 6502? Try slowing this down to slow the 6502.

If you don't get anywhere I may be able to help further after the weekend.

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Links to other interesting threads:

· Home of the MultiBladeProps (SixBladeProp)
· Prop Tools under Development or Completed (Index)
· Emulators (Micros eg Altair, and Terminals eg VT100) - index
· Search the Propeller forums (via Google)

My cruising website is: ·www.bluemagic.biz

Bamse

I don't know why the DS1245 didn't work and the 62256 did...
The 65C02 is feed by 5V and I think the Prop clocks it around 3.5 MHz.

I checked out Future Electronics and I'm going to order some of the AS6C1008 tomorrow.
Another idea I got is that the WDC65C02 does work at 3.3V and maybe I should just get everything running a 3.3V.
The 65C02 I have should work at 14MHz for 5V and 8MHz for 3.3V.

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Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

Ale

The LS logic should be changed for 3.3V, I don't know which family comes in DIP and handles 3.3V though :-(

Bamse

I think the 74HC244 should be OK for 3.3V, the LS and HCT probably don't work.
At least the Data sheet for 74HC244 say 2.0 - 5.5 V.

I ordered a few of the 128 KB memory chips from Future Electronics, they run at 3.3V so I think I have all the components needed to convert to 3.3V...

Just to give you guys a hint about a future project, I ordered a couple of Z80s as well...

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Living on the planet Earth might be expensive but it includes a free trip around the sun every year...

Experience level:
[noparse][[/noparse] ] Let's connect the motor to pin 1, it's a 6V motor so it should be fine.
[noparse][[/noparse] ] OK, I got my resistors hooked up with the LEDs.
[noparse][[/noparse]X] I got the Motor hooked up with the H-bridge and the 555 is supplying the PWM.
[noparse][[/noparse] ] Now, if I can only program the BOE-BOT to interface with he Flux Capacitor.
[noparse][[/noparse] ] I dream in SX28 assembler...

/Bamse

Baggers

Cool, I'll be looking forward to seeing a Prop+Z80+Ram [noparse]:D[/noparse]

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http://www.propgfx.co.uk/forum/·home of the PropGFX Lite

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