Hansel's Disk Controller

[Tom Lake]

When I uploaded the MITS sketch to the ATMega that goes on David Hansel's floppy disk controller card, I got this message: 

Low memory available, stability problems may occur.

Is this normal or might I have some switch set wrong?

[Giovi Alex]

do you mean the "ArduinoFDC", the project written by David Hansel that uses an Arduino to control a real floppy drive?  (https://github.com/dhansel/ArduinoFDC)
Or are you talking about another sketch?

If you're talking about another sketch, I'm curious to know about that.

If you are referring to the ArduinoFDC, I tried to upload it to an Arduino Mega, an Arduino Micro Pro (iirc) and Arduino Uno without problem. I didn't try to connect a floppy drive yet, though...

[da...@hansels.net]

I assume you are talking about the 88-DSDD card for the I/O bus. That message is normal. The sketch uses
a lot of memory but there is enough left for what it needs at runtime. There should be no stability problems.
The Arduino compiler is just a bit cautious because if you don't know what you're doing you can shoot
yourself in the foot quite badly if you don't have enough memory left at runtime.

[Tom Lake]

Whew! I'm glad it's not something I did wrong. Yes, the 88-DSDD is the one. I wasn't aware you had more than one disk controller available.
Thanks!

[Tom Lake]

No, I meant the 88-DSDD card. David has created several cards that plug into a backplane which can be connected to an Altair-Duino. They allow the AD to use real peripherals such as a cassette recorder, disk drives, Centronics printer and a paper tape reader. 

https://github.com/dhansel/Altair8800-IOBus

On Wednesday, October 20, 2021 at 11:17:12 PM UTC-4 strava...@gmail.com wrote:

[Giovi Alex]

thank you! I didn't know about that. Quite interesting!

[Giovi Alex]

does anybody  supply the PCBs? it will be quite expensive (at least here in Brazil) to build one per kind in some local factory...

[Tom Lake]

Only the Gerber files are supplied. you have to send them to a fab house to make the boards if you don't have the equipment yourself.

At one place, the minimum order is five boards but they're only $2.00 USD each (plus shipping) so not too bad. If you know any friends who want one, go in with them to place an order.

[Walt Perko]

Hi, 

I have an Arduino UNO board, but I cannot figure out how to program the ATMEGA328P-PU with the .HEX files for the ACR Cassette board and Disk Controller board.

I have no idea how to program the ATTiny85 for the other .HEX file either.  

[Tom Lake]

You need a hat for the Uno that has a socket for and allows you to program the chip.

[Walt Perko]

Hi, 

I did a quick Google search for "Arduino UNO HAT" and got pictures of all sorts of different devices that all seem to solve different user needs.

I kind of expected to see a "shield" that has a ZIF socket on it, but I don't see anything like that in the searches ??? 

Is there a link to at least one "HAT" so I can see exactly what I need? 

[Terry Fox]

Walt,

"Arduino Uno Hat" would yield generic hats/shields of all kinds.  You need to specify more details, such as adding "ATTiny 85 programming" to such a search.  Otherwise, you are searching for the equivalent of "Altair S100 board" while looking for a specific I/O board.

I believe Amazon has small USB boards that you can plug into just about any USB port, that has an 8-pin socket for programming ATTiny 85s, at a pretty cheap price.  Here is an example:

Amazon.com: Tiny AVR Programmer : Electronics

Terry, N4TLF

[Walt Perko]

Hi, 

How do I program the ATMEGA328P-PU chip?  

When I try File - Open - ACR.hex  I get this error;

Bad file selected

Arduino can only open its own sketches and other files ending in .ino or .pde

What do I use to program the 328 chips?

[Giovi Alex]

somewhere in the adwaterandstir site there's the Arduino firmware for Arduino Due programming. It comes with .bin files, the bossac.exe file and a .bat file; maybe you would try that (however you can't upload an hex file afaik, you need the .bin file)

[da...@hansels.net]

There are many tutorials on the web for programming an ATMega328P and ATTiny85
using an Arduino UNO. For example

ATMega328P: https://www.brennantymrak.com/articles/programming-avr-with-arduino.html

ATTiny85: https://create.arduino.cc/projecthub/arjun/programming-attiny85-with-arduino-uno-afb829

Note that I have not personally tried either of those so I can't vouch for either of them (I use a
MiniPro TL866 clone from EBay). But they should get you started and give you some keywords to
search for if you want to look for different instructions.

[Tom Lake]

The files that include the Gerbers include an Arduino sketch.
The shield can be found here:
https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313&_nkw=avr+isp+shield&_sacat=0

[Walt Perko]

Hi, 

Using the XGecu TL866 II Plus chip reader/programmer I was able to program the ATtiny85 and the HardDisk I/O board ATMEGA328 U sans errors, but the ACR program fails on its ATMEGA328 U ??? 

[da...@hansels.net]

Have you tried a different ATMega328? I don't think the program itself can cause programming to fail
so I would assume it's a problem with the ATMega chip.

[Walt Perko]

Hi, 

I was wondering about the two 328's I bought ... I ordered ATMEGA328P-PU chips, but on the chips it say's something different;  

Still, the other chip seemed to program okay, but I can't test it yet as I'm still waiting for parts to finish building everything.  

[villa...@gmail.com]

On the TL866 are there not Fuse Bits that need to be set for an ATMEGA328  ?

[Walt Perko]

Hi, 

Nothing in the manual about "Fuse Bits" ... 

[da...@hansels.net]

There are, but as far as I know those do not affect whether the programming succeeds or not.
The programmed chip may not work if fuses are set incorrectly but the programming itself should succeed.

[Frank P.]

The P after the 328 stands for Picopower meaning it's a newer and lower power consumption chip. Yours pictured is not. Otherwise they should work the same. My µKenbak-1 kit came with the "ATMEGA328P U"; the number at the top is the same as yours; the number at the bottom is different.

[Walt Perko]

Hi, 

I tried the chip on my Arduino UNO board, it fails there too.  I found that I was shipped the wrong chips so I'm returning them for the correct chips.