Author Topic: Frequencies / Protocol of FDD port at the 36 pin connector or 26 pin connector  (Read 8273 times)

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Offline Audronic

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@RobertM


How is the Project coming on ??


Ray
Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
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Offline RobertM

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@RobertM


How is the Project coming on ??


Ray

Hi Audronic (Ray),

It was all put aside because my son had come to visit. He has just left recently.

I had a computer crash so I am having to start over with a couple of things. I have three projects that were put aside. One is a TRS-80 clone with VGA output and the other is a custom retro computer (also VGA) and this one of course.

I was just now thinking that I should order a Disk On Module for this.

Here is were it was 'at' from memory -

At one stage I did see a "Hello World" on the CPC that was written to the CF card on the PC so I had something going. I was getting memory corruption and I was suspecting a PSU. I did go and buy another PSU though. I don't have a scope for debugging analogue issues.

Also, both CF cards I am using came from the same place in China so I should go and buy another just in case both are faulty.

I was at the point of re-viewing all stages of the build - pinouts - specs. I remember that one of the CPLDs that I use here has a pinout error on the data sheet so that may be an issue.

So I am going to start over. I have to set up the project first as it's been packed away.

I have a logic analyzer here now so perhaps I will set that up. I have the Altera and Xilinx platform running on my laptop now as well. The pore thing is only a duel core and struggles. The desktop was a quad core - I might try to fix it.

So - I should be back here this coming week hopefully - if I don't end up spending too much time on the other projects.

On another note I have been completely retro and using wire wrap for one project lol.

Offline Audronic

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@RobertM

Ok. The Pause that refreshes (an Old Commercial) ?

The DOM's are very handy, small power requirements , compact , can plug into connectors (No Cables) , small size.
We ended up using some on a Low cost Ide drive for a Model 3/4 which worked well.

I have just come from the Trs-80 world Models 1/3/4/4p/System80 (Video Genie)
You were adding VGA to what model Trs-80.
Wire wrap os ok for prototypes.

Keep going

Ray



Procrastinators Unite,
If it Ain't Broke PLEASE Don't Fix it.
I keep telling you I am Not Pedantic.
As I Live " Down Under " I Take my Gravity Tablets and Wear my Magnetic Boots to Keep me from Falling off.

Offline RobertM

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@RobertM

Ok. The Pause that refreshes (an Old Commercial) ?

The DOM's are very handy, small power requirements , compact , can plug into connectors (No Cables) , small size.
We ended up using some on a Low cost Ide drive for a Model 3/4 which worked well.

I have just come from the Trs-80 world Models 1/3/4/4p/System80 (Video Genie)
You were adding VGA to what model Trs-80.
Wire wrap os ok for prototypes.

Keep going

Ray

I will give a DoM a go but it will take time to get here.

I am not so much "adding" VGA to a TRS-80, instsead I am trying to clone a TRS-80 from the start but using VGA out instead of composite. I may also use a PS2 or USB keyboard. In fact I may build it into a PC keyboard.

At the moment I have just a sRAM 128kB, FLASH 128kB, a Z80 and a 240 LE CPLD.

I can't find decent CPLDs that will run with 5 Volts - all I have here are Xilinx XC9536XL, XC9572XL and Altera EPM240, EPM570 - very small CPLDs.

The TRS-80 is becoming a problem, I can't fit the character ROM into the CPLD so both the FLASH and the sRAM have to be accessible by both the CPU and the Video CPLD.

Anyway I will plot along.

If you are interested in my other project then many of them are here -
https://hackaday.io/Hacker404

Offline Munchausen

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About the flash air - I have played a bit with the transcend wifi SD. It's the same thing as the others (runs linux on an embedded SoC), but it has been hacked so you can put your own code on it and if you crack it open you can solder on to the serial port pins. I've managed to compile the ppp kernel module for mine and run pppd over the serial port, so if you want something like that then it could be useful. (In my case I am using it to provide both storage and networking on a psion series 5mx - which can talk ppp over serial). Good luck getting on the hackaday connecting to hackaday with a retro computer thingy  ;)
« Last Edit: 00:33, 25 April 16 by Munchausen »

Offline RobertM

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About the flash air - <snip>
 Good luck getting on the hackaday connecting to hackaday with a retro computer thingy  ;)
I read reviews about 3 different ones before choosing the SanDisk Eye-Fi. One of them would onlt set up as an access point. The one I have connects to my existing Wi-Fi LAN.

I have full documents here somewhere on hacking on of them but I am not sure which one.

I am using the Eye-Fi for my camera at the moment and it woks well for that. I will get back yo the Amstrad-Wi-Fi thing after I have the CF memory sorted and when I do, I may use a different Wi-Fi / SD card or just a wireless card / module.

Offline Munchausen

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I read reviews about 3 different ones before choosing the SanDisk Eye-Fi. One of them would onlt set up as an access point. The one I have connects to my existing Wi-Fi LAN.

I don't know if you're a linux/unix user but if you are you can log in to the transcend using ssh (or serial) and configure the wireless however you want. I don't know how true this is of others, I know that some of them didn't appear to be very hackable, others use essentially the same hardware as the transcend. Some are not running linux at all.

If you want something that you can just talk to over serial and that has a built in TCP/IP stack, take a look at the ESP2866 modules.

Offline RobertM

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I'm not very good at Linux except where it is running Apache.

What is the ssh port number (22)?

I can get the IP from the DHCP server and try to connect via a port number and see what happens.

Offline RobertM

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Well the Disk On Module (DoM) arrived today. It was a long time coming.

I am starting over before I get carried away. I have tested the board for continuity and routing. Next I am going to check the VHDL constraints file.

I have already found one problem (some time ago) in that I mixed up the three port address signals (A0, A1, A2). I just fixed that in software for now.

I am hoping that the DoM wont have signal  level issues. The CF card requires Voh of 4.7V (CMOS) and the noise margin is small.

Wish me luck lol. I will be back to it tomorrow.

Offline RobertM

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Sigh, got distracted with other projects but I did do some google 'research'. Someone else tried exactly the same thing with exactly the same CPLD and it had problems for them. Even though they didn't specifically say it was the low noise margin, I am going to go with that being the problem for now.

So in theory the DoM should work with the LVTTL CPLD as it has TTL levels and not CMOS levels like the CF card. I will give it a go when I next set up that project on the desk.

The other person reverted to using 5 Volt XC95xx chips instead of 3v3 XC95xxXL but the former are obsolete now. Dam lol I just bought 100 XC9536XL's.


Offline RobertM

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OK This was on the back burner for a long time.

I ordered a Disk On Module (DOM) and tried it and it worked first time.

I then made an adapter and tried a 2.5 inch PATA Hard Disk Drive and it works fine to. I had to use a second power supply though.

So the problem wasn't between the 3v3 CPLD and the level translator - the problem was between the level translator and the CF card. The drop in voltage on the 5 Volt line meant that the Voh from the level translator was lower (with noise) than the CMOS Vih of the CFCard (4v7 from memory).

Anyway now I need to worry about software.

I previously looked inside the CPC 6128 and it didn't look like I could fit a ZIF in there for the rom(s?).

Is there an existing TSR or RSX that extends the existing Amstrad Disk functions to an IDE device?

Is it better for me to mod a ROM or just add and external ROM?

My setup is the eight port addresses (I think 4 are used in 8 bit mode) that other older CPC-IDE hardware has. ie - It's a standard 8 bit IDE port like on 8 bit mode of the original IBM AT.

That might sound confusing ! and it is confusing ! There is an 8 bit AT mode that it NOT an 8 bit XT mode and that is what has been used by others and that is what is supported by CF cards! CF cards do NOT! support the 8 bit XT mode.

What I want is to add the RSX "|c" that extends the featured like RUN" load" cat |dir to the hard drive.