Troubleshooting a W65C134SXB

[bexsella]

Hi all, I am new to the 6502 space, and as a embedded SWE I have found that there are simply too many bits in my day. So, I decided to buy a W65C134SXB as a Christmas present to myself.

Now, I have been following the Getting Started Guide, and installed the requisite drivers for the FT232. However, I am getting no serial port connection whatsoever. Running up Device Manager shows no active COM ports. Attached is the curreny visual state of the board, with some lovely LEDs lit. Any insight into this would be appreciated, I could well be missing something blatantly obvious, but I am getting the uneasy feeling that I may have a defective board here, possibly due to inadequate shipping from Mouser.

[GARTHWILSON]

Welcome.  I don't have the answer to your implied question, but I will comment that it is extremely unlikely that you received a defective board.  Mouser is one of the legitimate distributors our company buys from regularly, and of all the probably hundreds of thousands of ICs I've been partly responsible for, we have never received a defective one, AFAIK.  The 6502 primer however has a few paragraphs about static-handling precautions on the 74xx logic familes page, under the heading "Static-Handling Precautions" 3/4 of the way down the page.  Be sure you follow those to avoid damaging new (or any other) CMOS parts.

[bexsella]

Noted, and book marked. I happy to report that this was operator error. The micro usb cable I had to hand was power-only. This is a humbling start, and a lesson to always check the cables.

[BigEd]

Welcome indeed... a nice start. Checking everything, including things which can't be wrong, is definitely one of the best practices!

[drogon]

Looks like your going now.. I have one of these too and have written some stuff about it here if interested..

viewtopic.php?f=1&t=7837

and on my own blog:

https://projects.drogon.net/porting-my- ... 5c134-sxb/

And yes, I've seen that issue too - with a cheap USB cable. The on board firmware tries to use hardware handshaking and (I think) if there is no serial then it gets confused. The LEDs are active low so come on until some code initialises the port and sets their outputs high.

Good luck with the board - as a microcontroller it's not setup the best way - I suspect some PCB routing is to blame for the output bit/port usage though, but if you want to get an alternative going, then you could do worse than start with my TinyBasic - but there isn't enough Zero Page left over to support EhBasic but if you want an utterly trivial run-time system so it could support EhBasic then that's included in my TinyBasic code as a separate entity. I did consider porting my RubyOS to it so I could run the much nicer BBC Basic, but never really found the enthusiasm for it.

You'll need the extra Flash/EEPROM chip though - almost essential unless you're going to download and run entirely from RAM.

Hope you can make something of it - do let us know what you get up to.

cheers,

-Gordon

[bexsella]

Hi Gordon, I did find your posts in the middle of this, ahem... troubleshooting. I brefily felt that I made a mistake in buying this particular bit of kit, but for three weeks of hacking around I think it's adequate. While reading your posts I did immediately regret not getting an EEPROM + Programmer with it, and with Christmas post being what it is, I'll have to grin and bear execution directly from RAM for a little bit (again, as this is a learning exercise I'm not to fussed by it).

BigEd wrote:

Good luck with the board - as a microcontroller it's not setup the best way.

I preferred your alternate wording:

Quote:

Zero page is where the hardware register are. What a cock-up.

[BigDumbDinosaur]

bexsella wrote:

BigEd wrote:

Good luck with the board - as a microcontroller it's not setup the best way.

I preferred your alternate wording:

Quote:

Zero page is where the hardware register are. What a cock-up.

Periodically, friendly debate starts around here about the value of mapping I/O hardware into page zero.  My opinion is doing so is wasteful of page zero and does little to enhance I/O-bound performance.    Other opinions are the opposite.  YMMV, as always.

[drogon]

bexsella wrote:

Hi Gordon, I did find your posts in the middle of this, ahem... troubleshooting. I brefily felt that I made a mistake in buying this particular bit of kit, but for three weeks of hacking around I think it's adequate. While reading your posts I did immediately regret not getting an EEPROM + Programmer with it, and with Christmas post being what it is, I'll have to grin and bear execution directly from RAM for a little bit (again, as this is a learning exercise I'm not to fussed by it).

You don't need the EEPROM to get going and you don't need a programmer either as it's capable of self-programming - however to save you the effort of writing code to do the programming, I do suggest you get my GIBL (TinyBasic) and run that on it from RAM.

The RAM version has some extra code in it that I use to put the tiny bootstrap kernel and the ROM version of GIBL in the EEPROM, but can be adapted to put code anywhere when you get an EEPROM for it.

If you get the .tgz or .zip file from here:

https://project-downloads.drogon.net/gibl/

then in the sxb directory there are a couple of srec files which are ready to go - so if you can download the ram.srec file, it loads in a $1000 then use the g 1000 command and it ought to fire up into GIBL/TinyBasic.

Also in the sxb directory there is a program called flash.tb and that has all the runes to let you copy stuff from RAM into the EEPROM.

ZP data used by the built-in monitor is a pain - it's not documented well at all and I had to dig through the source code to find out what it was using. (And it's not even all defined in one place either!) However from $D0 trough $FF is guaranteed to be free for your own use. It's not a lot but will get you going.

Hardware is from $00 through $3F.

But the first thing to do is get reliable downloading via the serial line going. Then you can send SREC files directly into it.

Cheers,

-Gordon