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CharlesMouse

Interest in Dual Serial / 80Column (CP/M) Board for the ADAM?

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The simplest way to test is to redirect the console output to the serial port under CP/M using the included CONFIG program (CP/M 2.2). Run the CONFIG program, follow the menus to load the tables from the disk, modify the I/O byte for the console, save back the tables to disk, then reboot. The I/O byte for the console will be assigned to TTY. All output meant for the screen should then go out the serial port. That said, I'm not sure how that will look on the terminal... Only one way to find out :)

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Ahh, thanks for that I shall give it a go and report back.

 

Um, I going to reveal just how little I know about CP/M - how does the OS 'know' how and where to address the serial hardware if I haven't loaded some kind of driver?

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Ahh, thanks for that I shall give it a go and report back.

 

Um, I going to reveal just how little I know about CP/M - how does the OS 'know' how and where to address the serial hardware if I haven't loaded some kind of driver?

The serial device settings can be entered using the CONFIG program. Now my CP/M experience comes from the likes of the Kaypro and TRS-80 where the serial port is already pre-configured in the BIOS and assigned to TTY, and I'm not sure how the various Adam serial cards fit into this.

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Attached is the "driver" disk for the MIB2, essentially TDOS with a special version of the install program that supports the MIB2 card. The installation program you want to use is the 80MIB458.com. Follow the prompts as they are self-explanatory. Make sure to assign CON: to SR1: (console output to serial). After reboot, you should theoretically see the Adam output on the serial terminal connected to the MIB2 card, assuming your prototype is fully compatible with it.

Let us know how it goes.

 

PS: I recently bought an MIB2 card, and will be testing it soon as above :)

 

EDIT: the 80 col program above automatically assigns CON: to SR2: (second serial port). No need to change that but you do need to connect to port 2, not 1.

Micro Innovations M.I.B. 2 T-DOS Utilities (199x) (Micro Innovations).dsk

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Attached is the "driver" disk for the MIB2, essentially TDOS with a special version of the install program that supports the MIB2 card. The installation program you want to use is the 80MIB458.com. Follow the prompts as they are self-explanatory. Make sure to assign CON: to SR1: (console output to serial). After reboot, you should theoretically see the Adam output on the serial terminal connected to the MIB2 card, assuming your prototype is fully compatible with it.

Let us know how it goes.

 

PS: I recently bought an MIB2 card, and will be testing it soon as above icon_smile.gif

 

EDIT: the 80 col program above automatically assigns CON: to SR2: (second serial port). No need to change that but you do need to connect to port 2, not 1.

 

 

Hi, sorry for the really slow reply - thanks very much for the driver file and the most helpful advice... Unhappily I've spent the last few days struggling to get the card working, but with no luck. From your helpful advice I'm now pretty sure it's not me installing the drivers wrong...

...which is a pain because I was pretty sure I'd found and fixed all of my hardware mistakes. I hope the issue is just the current prototype isn't working as a result of over-patching as it's got a fair bit of Kynar on it. Or, maybe I've got a bad IC or two... more stuff I'm waiting on!

 

Another post with more details shortly in the hope some kind soul can tell me what's wrong.

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Right, details. If anyone can tell me what's still wrong I'd appreciate the help. If nothing I'll assume it's just my current board is over-patched and too unstable to run.

 

So here goes:

 

Raspberry Pi:

Seemingly all good, and I have been sure to check I've got it communicating at the same baud setting as the ADAM, but no luck. The best I've managed is having the keyboard input under TDOS go berserk when I set it up to use a keyboard attached to the Pi for input just to see if I was getting any communication - I guess that suggests something is going on!

FTDI Adaptor:

As my board is basically a serial interface I tried using an FTDI adapter hooked up to a PC with TeraTerm acting as a console so I'd have full control over communication options. Also to see if it was a PI-specific issue. Again no joy on either serial port including trying alternate baud rates and parity settings, etc.

Pi Serial board:

As far as I can tell I've patched all the mistakes (maybe not!) and swapped out all the IC's for which I had replacements... still waiting on some IC's.

 

Design:

So I took another look at the MIB schematic (see attached) and the GAL code (see attached) and re-did the board from scratch (see attached).

Improvements over the old design:

-A much neater board, with fewer components to source

-All mistakes I'm aware of fixed

-Some changes to resistor values and logic in an attempt to improve stability of the board

...all good but my 'worry' is while I've come up with a 'better' design the fundamental function isn't any different from the way my thoroughly patched prototype board is constructed, and not working!

 

Specifics:

-Schematic:

I can't see any wiring mistakes on my part, the MIB original, or my interpretation of it's function

 

-GAL:

As far as the serial ports are concerned all the MIB boards are the same. So drivers shouldn't matter, and the schematic I'm using should be fine too.

The GAL functions I need to reproduce are as follows:

 

Duart RESET 1CH (Output) - SRST = IORQ & WR & A[7..0]==1CH

This is handled on my schematic with a couple of NAND gates and a 4048 (the one at the bottom) - it looks good to me but have I done something stupid..?

 

Duart I/O space 10H-1FH - SCE = IORQ & A[7..4]==0001B

Again handled by a 4048, the one higher up on the schematic. One of my mistakes, which I hoped patching the board would see the board come to life, was not noticing the IO space is a range not a single address. The logic only looks at A4-A7 for addressing. I handled this by just grounding the unused lines on the 4048. Again this now looks good to me but am I wrong?

 

I've added a couple of NAND (NOT) gates on the input line for the Pi for 'signal conditioning' in the hope this might improve reliability. I also added a test header so I can mess about with the communication lines to the Pi in case I got the wiring wrong - I don't think so, but I did check this on my prototype without any improvement.

 

As I'm running my board for TTL level serial I also changed the ports to standard FTDI ones and added some current limiting resistors for a bit of protection - again I'm not aware this will be a problem but as I'm not experienced with this UART you never know...

 

 

My issue is I have what I believe to be a good design that is compatible with any of the MIB drivers but my admittedly heavily patched prototype board doesn't work. I'm therefore wondering what I've missed / done wrong and as a result a bit reluctant to send of for a new batch off boards based on this latest design in case they are duds too. Thoughts would be very much appreciated.

 

PS:

In case any are worried about this stripped-down iteration never fear. Courtesy of the breakout header I already have daughter boards designed for ROM, Parallel, AY sound... but they are of no use if the primary board won't work.

post-35234-0-97277000-1560012134_thumb.png

post-35234-0-94827400-1560012146_thumb.png

FW_MIB3G1.pdf

MI_MIB2B_SCH.pdf

Edited by CharlesMouse

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