Sporniket's log on hardware stuff

[ijor]

The level of details is seriously overwhelming my computer, but the ground ring is done.

Awesome job!

[sporniket]

Thanks everyone

After doing a little bit of via stitching for the ground, I fixed some ERC and DRC errors, I had some connections loose.

Now working on the silkscreen, I feel that the work will be done this week-end or next week-end, if life allows it.

[sporniket]

EDIT : this project is ready for its own topic --> viewtopic.php?f=31&t=7025

Two last details, that I added on the bottom silkscreen : 


For the MMU chip, I have spotted pins for MAD9, RAS1, CAS1L and CAS1H, for RAM expansions.

Capture d’écran du 2024-05-24 23-44-15.png (55 KiB) Viewed 1225 times

For the MFP chip, I have spotted the trace to cut to install a mod like RSVE

Capture d’écran du 2024-05-24 23-54-33.png (14.99 KiB) Viewed 1225 times

[DoG]

Very smart to add to silkscreen. Maybe locate and point out ACSI10 for when you install, for example, IDE.

[sporniket]

good note, do you have a reference design ? I have 3 traces : 

• From ACSI port, pin #10 (I suppose this is the trace that you have in mind ?) to U35 (74x04) pin #5
• "ACSI_INT", from U35 pin #6 to U40 pin #5 (to be NOR-ed with Floppy drive INT as MEDIA_IRQ)
• "MEDIA_IRQ", from U40 to the MFP pin #27

[sporniket]

Today I got some PCBs delivered, one for a project that should be considered vaporware until something concrete emerge, and one as a helper for my next project.

So the first one :

2024-07-08--00-plcc-68k-cpu-extension.jpg (161.9 KiB) Viewed 672 times

I mentionned somewhere that I fancy to remake the STe motherboard with a compacted size (final target size being that of a B5-sized sheet of paper), using CMS for the passives to save space. But my attempt was not very fruitful, as I also wanted, among other things, support external blitter (at least for mk1), support PLCC-68 packages as well as DIP-64 packages for the CPU (for, you know, extension and accelerator made with the DIP-64 format), and rearrange the ports for "more practical layout". I was demotivated when trying to route around the GST MCU, as my board layout was made irrespective of the pinout of that IC, and that is asking for troubles... For the record, I also tried to see how it would goes with ATX format, but after an evening of work I felt being checkmate. And thus I left that project like that.

Flash-forward up to a few monthes ago, I realized that I could reach my horizontal surface target if I was willing to stack some part, in the spirit of the Falcon extension port. After a quick check, I decided that the Falcon port was not suited to my project, but I kept the idea of a 2-parts expansion connectors that would take the signals of the 68k and the blitter, and specified said connector (https://github.com/sporniket/reste-mign ... blitter.md ) . Then I designed that CPU board. So at least something has been materialized.

This board was also made as a drill about routing, where I followed principles of orthogonal routing, and at the same time broke from the 45-degrees turns to use free angles. Also, this is a 4 layer board with 2 ground planes inside, and I took care to space vias enough to not create rifts inside those planes.

So once again, don't hold your breath hoping to see a remake of the STe, yet. But if that CPU board can be usefull somewhere, that would be great.


The second one :

2024-07-08--01-component-holder.jpg (72.45 KiB) Viewed 672 times

This summer I plan to assemble the remake of the Thomson MO5 that I reverse engineered recently, and this PCB is designed to hopefully help me being efficient by preparing a set of passives (e.g. all the resistors), meaning selecting the appropriate value, fold the leads, and place them on this holding plate, and then pick each of the prepared component one by one, place them and solder them.

I do hope that I will feel efficient using this, experience will tell. If successfull, this component helper will also help me when I will feel like assembling the Atari 520ST that I recently reverse-engineered too, most likely at the beginning of next year, if all goes according to plan (money and time).

[Cyprian]

the STe motherboard with a compacted size sounds awesome.
It would be cool to have the STE mobo for the short ST case.

[Darklord]

Hmm....or adapt one to a STacy case? Ah, the possibilities!

[sporniket]

Yes, a succesfully compacted STe motherboard enables a lot of cool possibilities *o*

Anyway, beside a DIP-64 version of this extension and the blitter version, I plan to specify and implements similar expansion connectors (but physically different of course) for 3 other parts : RAM, ROM and MFP+RS232 conditionning. Then I will be able to go back to the motherboard.

Time will tell...

[nokturnal]

The level of details is seriously overwhelming my computer, but the ground ring is done.

Great work I really like short STs.. Put blitter somewhere and it will be ace