H4 schematic

[exxos]

H4.jpg

Download hi-res version.

H4.zip

PARTS LIST

parts.zip

H4IC.jpg

HI RES IC LAYOUT

H4IC.zip

BOM V1

BOM_V1.zip

UPDATED BOM (27/10/19)

STFM_H4.zip

UPDATED BOM v3 (31/10/19) fixed C10,C46,C47,C48, added farnell & rapid parts (prices listed are for rapid & farnell)

STFM_H4v3.zip

UPDATED BOM v3a (03/11/19) fixed wrong rapid code for R14,R36,R37

STFM_H4v3a.zip

OPENBOARDVIEW FILES HERE
https://www.exxosforum.co.uk/forum/viewt ... 778#p38968

[PaulJ]

Just looking over the layout for the H4. Looks great!! Guess I'll start sorting out all the xtra stuff I had from the REMAK build.

Couple of questions... I see the floppy mod GAL.. how do you plan to handle it.. do I need to order GALS or are you selling pre-programmed GALs? Either way is fine by me. :) Also the VGA connector, I assume it hits the normal video connector hole that will need to be enlarged?

What kind of chip is located to the south of the MFP 68901? I'm assuming its PLCC52?? What is its purpose? Do we need it initially and if so how is it going to be handled?

Anyway great job guys. Can't wait to get started. :excited: :excited: :excited:

[exxos]

Couple of questions... I see the floppy mod GAL.. how do you plan to handle it.. do I need to order GALS or are you selling pre-programmed GALs? Either way is fine by me. :)

I don't know yet, but I need to try it all out before it hits users hands. I can't test and debug until I have a built board to try it out on.

Also the VGA connector, I assume it hits the normal video connector hole that will need to be enlarged?

Yeah, if you want to use the VGA connector then you will have to edit the case hole a bit.

What kind of chip is located to the south of the MFP 68901? I'm assuming its PLCC52?? What is its purpose? Do we need it initially and if so how is it going to be handled?

Its just a alternative package 68901, like the GLUE & MMU have 2 package versions. So you can re-use the DIP 68901 just like before. That socket was only really added as there was space for it, and I have a bag full which I have nothing to test on :) Its unlikely going to be any use for anyone else.

[exxos]

I forgot to mention (bit early yet for more info on parts) but the DAC and OPTO I will be supplying for free for people who pre-order. So you don't need to worry about those.

Its possible I may do a very small kit just with a few basic parts, maybe the SIL's and caps.. simply because I have a large stock of those anyway. Though I need to look into it all yet..

[DoG]

Great with option if it fits. So why not. Can't wait to get my hands on it.

Is it suppose to be 16 Mhz right from the start or standard 8 Mhz? Or a switch between the two speeds?

[exxos]

Is it suppose to be 16 Mhz right from the start or standard 8 Mhz? Or a switch between the two speeds?

We are nowhere near finished with 16MHz stuff yet.

[PaulJ]

Exxos, I see there is a FMCII RTC on the board and a spot for the flashy clock. I'm guessing that the flashy clock will be an extra add on? :?:

[Icky]

Exxos, I see there is a FMCII RTC on the board and a spot for the flashy clock. I'm guessing that the flashy clock will be an extra add on? :?:

Flashy Clock spot is for the Flashy Clock v3 board and allows the use of the RTC and/or FlashROM.

Starting with the Flashy Clock v3 board we have built in the ability to either use it in an existing ST with the CPU plugged into the board or in the H4 without having to transplant the CPU.

[exxos]

FMCII was added ages ago. Flashy clock plus other things are still not finished yet. We tried to make as many provisions as possible for upgrades on the H2 but its difficult to design a motherboard to use upgrades which haven't been developed yet.

We did talk about adding stuff on such as IDE but we're out of time. Though with so many changes done on the H2 already it just wasn't a good idea to add anything else. Mostly we needed a fixed alpha with multiple 68k sockets so we can develop multiple addons at once. Of course the H2 had all the tweaks which people tested such as the video DAC, DMA fixes and piles of other things. So the H2 brings everything together. Plus with all the other optimizations its almost a complete redesign of the alpha.

Over the next year we will work on the addons. I really need to finish my booster work as well. But time is always short. Its possible it may take 2 years to complete all as we need to look into FPGA as well plus 16mhz etc etc. There a huge amount of work to do yet.

Meanwhile the H4 gets produced, with any tweaks which we end up doing and it will become the H5 most likely. This will be the stock board and I will keep producing that series while there is demand.

[exxos]

I've put up the first BOM list in the first post. I've called it V1 as , well, its version 1 of it :lol:

All mouser part numbers. As said before the DAC and OPTO will be included for pre-orders. I may do packs of some resistors and caps as I can buy a bulk lot of them...Will look into that now..

I listed 3M PLCC sockets. I strongly suggest people only use 3M branded ones.

Parts which are not listed in mouser are likely parts you need to rob from your donor machine. Though I have listed some parts which are also available in my store.