A500 trapdoor memory: free design

[katarakt]

Ok...i'll do it like this for b6, can you take a look if this is working or should i delete C11 ? Please confirm

If confirmed i'm going to order the next package of parts soon

[Mathesar]

Originally Posted by katarakt

Ok...i'll do it like this for b6, can you take a look if this is working or should i delete C11 ? Please confirm

If confirmed i'm going to order the next package of parts soon

I haven't populated c11. Same for c20. But they are not critical so you can populate them if you wish. C20 interferes a bit with some battery holders which is why I didn't mount c20.

I'd say your bill of materials looks fine.

[katarakt]

Thanks mathesar

Have ordered most parts now, finally to order capacitors and resistors ...and b6 boards, but i'll try to delete all jumper-traces because i plan jumpers for all...don't like to cut with a knife on pcb's ...have never done much eagle stuff so i hope i'll do it right

[Mathesar]

Originally Posted by katarakt

Thanks mathesar

Have ordered most parts now, finally to order capacitors and resistors ...and b6 boards, but i'll try to delete all jumper-traces because i plan jumpers for all...don't like to cut with a knife on pcb's ...have never done much eagle stuff so i hope i'll do it right

I have some red () b6 boards left. Since you are located in Germany I can put them in an envelope. Will only cost you 1,33 for poststamps

[katarakt]

Thanks matheasar, but i'm going to order a bunch of boards so i don't really need yours ...but, if you want to get really rid of them i'll take them for the cost of poststamps? Are you sure?

[esel]

hi, i got a little problem with the extension and the gary adapter.
I have a rev 6a Pal Amiga 500 and the latest revision b6 of the adapter.

When i set the gary adapter to 1 MB Chip and 1,5 MB Fast all is ok all memory test passed ok.

if i remove the trapdor expansion and jumper the Gary Board to 0,5 MB Chip and 512KB only all is ok i only have 0,5 MB Chip and no slow ram.

But when i insert a normal 512 KB extension i get 1 MB Chip and 0,5 MB slow ram ?

Of course the 1mb chip is not usable.

Other think is when i set the extension to 1 MB Chip and 1,5 MB Fast all is ok, but when i set my Gary adapter to 0,5 chip there is still 1 MB chip ram shown ?

is my gary board faulty ?

[PeteAU]

Originally Posted by esel

hi, i got a little problem with the extension and the gary adapter.
I have a rev 6a Pal Amiga 500 and the latest revision b6 of the adapter.

When i set the gary adapter to 1 MB Chip and 1,5 MB Fast all is ok all memory test passed ok.

if i remove the trapdor expansion and jumper the Gary Board to 0,5 MB Chip and 512KB only all is ok i only have 0,5 MB Chip and no slow ram.

But when i insert a normal 512 KB extension i get 1 MB Chip and 0,5 MB slow ram ?

Of course the 1mb chip is not usable.

Other think is when i set the extension to 1 MB Chip and 1,5 MB Fast all is ok, but when i set my Gary adapter to 0,5 chip there is still 1 MB chip ram shown ?

is my gary board faulty ?

Selecting 0.5 CHIP on the Gary board doesn't actually make it happen, you're just informing it you have 0.5. To really get 0.5MB you would need to return JP2 (motherboard) to the original factory position.

Maybe it's not so intuitive, but that's the way it's wired.

[katarakt]

I have ordered b6 boards now, i hope i've done this correct

Delivery needs some weeks and maybe i find the time around christmas to build a board. Meanwhile i'll order the rest of the parts

[katarakt]

I found something to improve in the layout, just a detail:

C20 will never fit because battery holder get's in it's way!! 2 Improvements will make it fit i think:

1. Change lead space straight from 2.5mm to 2mm -> now panasonic rad fr will fit with 5000h -> Panasonic EEUFR1C101( )

2. if changed to 2mm lead space straight ...pull it a bit to the outside on the pcb layout

With these changes i think C20 will fit much better

[Mq]

Originally Posted by katarakt

C20 will never fit because battery holder get's in it's way!!

I have soldered C20 and it fits perfectly without any problem. I have 100uF/16V. Look at the picture.

[katarakt]

Ok, your battery holder is different or...maybe b2 layout is different to b6 because at the moment i have only b2 board laying around on which i've tested my battery holder.

edit: ....oh....i got wrong battery holder! Why? Because peteau said "some cheap battery holder" ....totally wrong! There are totally different battery holder out there...now i have to buy other battery holder ....that's why a bom list with part number is so important !!!!

[PeteAU]

Originally Posted by katarakt

Ok, your battery holder is different or...maybe b2 layout is different to b6 because at the moment i have only b2 board laying around on which i've tested my battery holder.

edit: ....oh....i got wrong battery holder! Why? Because peteau said "some cheap battery holder" ....totally wrong! There are totally different battery holder out there...now i have to buy other battery holder ....that's why a bom list with part number is so important !!!!

My post actually says "Battery Holder: Some cheap ebay one.". There is no part number. They're $1 for ten.

[katarakt]

Thanks PeteAU

I used the excel-bom from kinmami which i thought is verified, so i bought digikey BS-3-ND wich is wrong ! The correct one is BS-7-ND !! .....'i've ordered them now

I'll post the updated bom for b6 after i got all parts and soldered everything from the bom to verify myself it is 100%

Ok..anyway i would recommend changing lead space straight from 2.5mm to 2mm -> now panasonic rad fr will fit with 5000h -> Panasonic EEUFR1C101( ) ...all the better panasonic capacitors have 2mm lead space straight

[katarakt]

I took a deeper look on the capacitors, there are no 2.5mm with diameter 5mm available! Distrelec has wrong information on website. The capacitor from kinmami bom has 2mm too in panasonic datasheet!! So...for improvement b7 i suggest C20 to 2mm lead space.

Or, with the correct battery holder, does capacitor for C20 fit with 6mm diameter?

[alexh]

Out of curiosity are there enough signals on the A500/A500+ trapdoor slot for a clock port?

If not can we work out what the missing signals are?

The only clock port solutions for the A500/A500+ are a CPU socket adapter which precludes installing most accelerators (Vampire etc.)

[demolition]

Originally Posted by alexh

Out of curiosity are there enough signals on the A500/A500+ trapdoor slot for a clock port?

You can also use the expansion connector as the ACA500 also has a clock port. But since that has all the signals from the CPU socket, that shouldn't be surprising. With the current Vampire core that uses the standard chip mem, a clock port in there could probably be made to work, however with Gold 3 it will probably not be possible to use any longer since the 68080 would use the memory on the Vampire chip memory.

Perhaps it would be possible to create some board that interfaces the Vampire SPI pins to a clock port (with the appropriate modifications in the core), but remember that the clock port is only 8 bits wide so it will always be inherently slow and probably wouldn't feel too useful with a 68080.

Which devices would you like to connect on a clock port? USB / audio card?

[alexh]

Not for me, but I was discussing what USB host solutions there were for a v500 Vampire.

At the moment the only good USB solution for an accelerated A500 (in it's original case) is the clock-port based Subway card.

Which is a shame because there are several free open-source HDL USB Host cores which take up very little space (perhaps their free license makes it impossible to be included in the closed source Apollo?)

The Xilinx FPGA at the Vampire's heart probably has unused gigabit SERDES capable of USB3.0!

[Mathesar]

Originally Posted by katarakt

I took a deeper look on the capacitors, there are no 2.5mm with diameter 5mm available! Distrelec has wrong information on website. The capacitor from kinmami bom has 2mm too in panasonic datasheet!! So...for improvement b7 i suggest C20 to 2mm lead space.

Or, with the correct battery holder, does capacitor for C20 fit with 6mm diameter?

My battery holder also covered C20. I just didn't mount C20 and the expansion card works fine without it.

[SukkoPera]

Originally Posted by Mathesar

I have some red () b6 boards left. Since you are located in Germany I can put them in an envelope. Will only cost you 1,33 for poststamps

Have you still got a couple of boards that you could ship to Italy?

PS: First post on this board, hello everyone!

[Mathesar]

Originally Posted by SukkoPera

Have you still got a couple of boards that you could ship to Italy?

PS: First post on this board, hello everyone!

Welcome to EAB then!

Yes, I have boards left. In red
Send me a pm.