Since whdload for the Amiga needs a lot of RAM for some games and my Amiga only sports a meager 2MB in total I searched for a way to get some more.
I stumpled upon the pcmcia-Slot for expansion pretty soon and had a look for expansion cards.
But damn, these are expensive! Even decade old sram cards for the pcmcia slot still cost a pretty penny these days.
But apparently some nifty guys from poland designed a new sram card, called the “Sakura 4MB PCMCIA SRAM”. You can find a link to their website here: https://sakura-it.pl/sram.php
Unfortunatly they stopped producing the cards a while ago. But being awesome dudes they offer the sources on github! So I decided to make an expension card by myself, using their sources.
But bummer, they are using parts you can’t find in 2018. Sure, you can get them from china salvaged from devices but meh, I like to get new parts. So I revised the circuit. It wasn’t that difficult, I had to change the sram IC, one other IC and the pcmcia connector. And since some guy said that the newest revision of the pcb on github seems to have problems I settled on the version 2.1. of the pcb as a base for the new revision.
The last thing to keep in mind is that pcmcia cards have to be exactly 3mm in height to fit into a pcmcia slot. I just designed three 1mm pcbs sandwiched together, you’ll see what I mean in the photos below. It would be nice to have a metal sheet to shield the pcb, but unfortunatly thats out of my realm of possibilities.
To sum things up here are some pictures of the build and a link to the sources:
Sources on github: https://github.com/jensma/ppa-pcmcia-sram/tree/master/board/v2.12018
I do have a favourite manufacturer for pcbs but sometimes its smart to check out the other fabs. I’ll test some manufacturers and write short reviews about them – this time: Seeed Studio Fusion – https://www.seeedstudio.com/fusion_pcb.html
I plan to do something with Nixies in the future but wanted to use a modern driver. After a bit of searching I found this awesome project: https://github.com/dekuNukem/exixe
Damn impressive and even open source! Since pictures are worth a thousand words have a look for the driver pcbs:
The edge cuts are clean, no frizzing at all. That’s pretty nice. Unfortunatly Seed puts a production code on the silkcreen. Meh, I really don’t like that.
Looking very closely you’re able to spot the marks of the e-test probes. Pretty impressive, I’ve never seen them before. I wasn’t even sure if my fab does this test.
Following up are some detail shots. The boards are good, but I spotted a small error at the end. Have a look for yourself:
The drills are all centered, the silkscreen seems to be offset by a bit though. Bummer.
The error is – excuse the pun – microscopic and won’t affect the functionality.
I know it sounds weird, but it’s a bummer you get exactly the amount of pcbs you order.
if you don’t order pcbs often this will most probably sounds weird. But usually you get at least one spare pcb. I like to use them for fitting tests or if something goes wrong while assembling.
Well, thats probably complaining at a high level.
Ah, what’s also pretty nice at Seed is the opportunity to order flex pcbs directly and having your boards plated with hard gold. That’s quite impressive, my fab won’t do that.
If you want to check them out by yourseld, head over to: https://www.seeedstudio.com/fusion_pcb.html
My RAM expansion for the Amiga 600 broke 🙁 Instead of getting an old and used one I decided to have a look if there are any affordable new expensions out there.
Unfortunatly, the cheap expensions got no RTC, that seems to be a feature of the expensive cards. Well OK, I’ll make my own then.
The gerber files at the end are licensed with the CC BY-NC 3.0-License.
To make it short: No commercial use, you’re free to use them personally and keep my name on it 🙂
Someone asked my about a scan of the dummy insert for the famicom disk system to protect its drive from dust. The rar file below contains a high res scan of the insert, the *.psd-files are ready to print. The thickness of the insert is about 1.9mm.
Just click the image to download the files: