Is This Australia's First PC? Part 3

PBUFF

A few years into the TRS-80, I designed a printer buffer based on the Z80. Printers of the day had no memory, so when you went to print a large document, your PC was completely tied up during the print. PBUFF was a printer buffer that could be configured from 8K to 4MB of DRAM. Hardware memory interfacing was done with only a single 74LS00 and a 74LS04. The magic was achieved with software and no hardware multiplexing was used. To my knowledge, I am the only person who was able to achieve this result.

PBUFF sold over 4000 units worldwide, well before the internet was known.

Reference:

Dontronics z80 Files.
Electronics Australia Magazine Apr-94
Silicon Chip Magazine Oct-89
Australian Electronics Jan-88 (PBUFF memory secrets revealed.)
Australian Electronics Mar-87

PBUFF unit shown has a serial interface board fitted on top of the PBUFF board. This allowed for serial or parallel in, and serial or parallel out.

There were many optional boards added to PBUFF.

An interesting footnote to PBUFF:

To help protect the EPROM software, I swapped data bits 6 and 7 to the EPROM socket, and shuffled the firmware to suit. I inserted some interesting text to throw off would-be pirates, however with the success of ZLOAD, I had to let the cat out of the bag, as many users wanted my boards just for Z80 development. This meant that 2 tracks had to be cut, and 2 jumpers connected to make it look like a normal data bus layout. I eventually made this easy by placing pads for this job on the board.

Additional Info: The image of the ROM dump below shows what potential pirates find. I inserted the "Oohey gooey" text as a decoy to mislead pirates attempting to steal my PBUFF code, and this text was only visible when Data bits 6 and 7 were swapped. As PBUFF and ZLOAD gained popularity, this caused significant confusion among ZLOAD users, prompting me to reveal the truth. In the final version of the board, I corrected the issue with the swapped data lines but designed it to allow for an easy swap of the data signals, ensuring compatibility with any PBUFF ROM.

Why Dontronics?

As my product range grew, I seemed to have a (bad?) habit of including "Don" into the product name somewhere. We even came up with a few un-printable "-don" names, that we joked about.

I first registered a business in 1964, and by 1995, felt I needed to come up with a new business name to match the type of market I was now involved in. We had to nominate five names in order of preference on the business name application form, and I came up with various combinations of "Micro" and "Electronics". My wife Cheryl threw Dontronics into the ring, as we were short on the five names needed. Of course, it came back with Dontronics winning the bid, a name I hated at the time.

Now, it has become a way of life. I was able to tell my boss where to firmly place his job, when I was 56 years old. A bold move at that age I guess. I have been fully self-employed since 1999, and currently employ one daughter full time and one part time. It's a nice feeling to be able to do that. I'll be 74 in April 2017, and hope to keep Dontronics going for a few more years into the future.
Note **** I retired the Dontronics business on the 30th June-2018, the end of the financial year, as I was past 75. That is 60 years that I had paid taxes.

My Mate Mick

A very special mention of my very good friend and right hand man, Mick Gulovsen. I met Mick at a TRS-80 User Group meeting in the very early days. He was hanging onto the right correct hand end of a logic probe, and I was silly enough to think he knew what he was doing, and introduced myself. He's been drinking my beer ever since, and I'm still trying to teach him how to use that logic probe. :-)

My Mate Mick

9-Sep-2008 Art Clarke wrote:

G'day Don
Read your page on the TRS80 with some amusement.

Rest assured that your machine wasn't the first around in Oz but would have no difficulty winning the 'most hacked'.

When Tandy announced the M1 in USA I was working in Woomera SA and had a few USAF personnel as both close neighbours and mates. One of those mates (VS) and I got together and purchased two TRS80 Model 1 machines in USA and shipped them to Australia, arriving in November 1977.

Not hard to do when you understand that USAF personnel going back to the States were willing to take our cash with them (in their account of course), purchase the desired item locally in USA and then have it shipped to their good pals via MAC flight. Naturally these arrived as 'gifts' to fellow USAF personnel so the one lonely Australian Customs officer wasn't able to do anything about it. After all, the things were going back to the States when those personnel left, weren't they?? Funny how they were 'dead' and given away as scrap about then!

Didn't take long to rework those to 16k Level II, one of which even had genuine Tandy ROMs in it. The other had EPROMs and neither of them had Tandy supplied 16k conversions.

VS later brought in a Tandy expansion interface which proved to be a real PITA, whereas I brought in the first version of the LNW interface as a bare board. That proved to be a much better solution once built, although it too had to be hacked a little to debug it. Feedback of what we found resulted in the improved v2 LNW board which went into all the kits and which won us a couple of new boards for our trouble.

By this time we had realised there was no substitute for the best quality components we could lay our hands on, so being good little fellows we used both his employer (USAF) and mine (Defence Aust) to source what we needed through the wonderful stores systems they both provided.

Both of us were already pretty electronics hardware savvy so didn't take us long to figure a good logic analyser would be rather nice. A bit of fancy footwork and USAF suddenly found itself the proud owner of a lovely HP manufactured unit. Just happened that VS was responsible for oversight of that sort of equipment too. Of course, one needs a decent 'scope too, so Defence Australia found a need for a nice shiny new dual trace unit (also HP). Never seemed difficult for us to have either or both around when we needed them, either.

Not too much later the LNW-80 main boards were being developed - around mid '79 from memory. One of those duly arrived and was soon assembled and put into service, again being hacked and debugged.

All through this, VS and I were continually adapting and adding to the machines, sometimes even with hardware sourced from yourself.

One of the more adventurous efforts was building & installing a sub board for a new gee-whiz RTC, mapped into memory just above the video hardware, and then hacking the NewDOS-80 OS we were using so that it read the time from the RTC. Quite a bit of patching plus a rethink to put the I/O routines in a small ROM also memory mapped and it worked virtually transparently. Even got the OS to set the time happily although we never did get around to patching the ROM code to use the RTC.

Enhanced graphics was another mod, port switched to overlay the ROMs, a nightmare when it came to hacking the OS to make it all transparent. We did get it done but were never all that happy with the implementation.

A pair of AMD math & arithmetic co-processors (921x's) also went into my machine, VS didn't see a need for it (but he wasn't driving a bloody great antenna array like I was for my amateur station). After several EPROMs got burned with hacked code, even Level II BASIC was using them for single and double precision arithmetic. Even SIN, COS, TAN and EXP were decently quick after that.

Not surprisingly, one common mod to each of our machines (there was a third by early '78) was to scrap the horrible cheap keyboard and contacts, replacing it with a Keytronics manufactured unit of much better quality. Access to gold plating facilities in Defence to eliminate issues with the contacts in those just finished it off nicely.

Somewhere along the line someone (either VS or BK) decided it would be a good thing to have sound. Not the beep stuff then being played with, they wanted full-on software driven audio output. It did get done but I sat back and watched that little circus.

All the machines had double density conversions along with at least two disk drives, purchased as soon as we realised how much of a PITA that bloody cassette tape was and immediately we knew the Expansion interface would allow us to get rid of it. Of course the DD conversions happened a little later, the first of which was a kludged add-on based on the new gee-whiz WD 179x series chips. That gave us LOTS of headaches getting the OS to work with it initially, then NewDOS-80 patches became available and sorted that out.

Funny the people we got to know, probably because we were either military or civilian contractors there was no problem contacting people like Randy Cook, Bill Gates etc. Of course, they were also just starting out and it was all something of a wonder to most of them ("jeez, I'm actually making a living out of this stuff!" was a familiar comment).

I think there is still one of your PBUFFs around somewhere! Probably residing on a shelf in the storeroom near the LNW-80 that's built into a Beehive B100 case. That unit came about in an attempt to reduce RF hash from the LNW-80 in the shack and reasonably successful too I might add. A spray coating of nickel rich paint on the inside of the case plus some extensive RF suppression on cables and ports brought it down to an acceptable level.

Anyway, enough reminiscing, time to get to a bit more software development for the AVR ATMega128 board I'm fiddling with. Don't those things make the old TRS80 look pretty sick!!
regards Art C

9-Sep-2008 Don McKenzie wrote:

G'day Art,

Thanks for your very interesting email. I see you also have a lot to reminisce about regarding the TRS-80, and can understand how the combination of the USAF and Defence Australian, beat me to the punch, when it comes to having the first (PC?) TRS-80 in Australia. I must ask you, did it survive? Do you still have it? I know others would be interested in reading this account of your involvement in this evolving period in Australian computer history, and would like to add your email to my TRS-80 page.

I would like to use your name only, not any email or other personal details, as there may be pending customs, and other 30 year old legal issues. :-)

(IE: Hands up those who didn't have a set of level II's in EPROM?)
Cheers Don...

PS, Art gave me permission to post his email on this page. It appears that the TRS-80's mentioned in his text have gone to heaven.

13-May-2010 Trevor Moore wrote:

Hi Don, I read with great interest your article on the old trash80! brought back many happy memories However yours was not the first, I bought mine mid 70's 26101 d Ser 025581. Still have it in a box up the shed. regards Trevor Moore.

(Trevor provided pictures of the unit, including the serial number he mentioned)

Yes I have lived at Mt.Martha for quite some time but not in the 70's. I was not aware of the user group at that time.
I bought the unit from a Tandy store in Sydney rd Brunswick, the salesman didn't know what I was talking about and I had to show him a catalogue from the US. and they ordered it in for me.

I fiddled with many modifications to my unit including lower case mods, and a high speed tape interface, however I always wanted to add a printer but as it did not have the expansion interface I had no serial port.

I was an avid reader of Micro 80 I think it was called, a US magazine for enthusiasts and I came across an interface project for Connecting a teleprinter via a current loop, I bought an old TAB terminal which was the size of a small desk which contained a very ancient Teleprinter, you may be familiar with these terminals, what a mechanical monster ! however with a bit of translation code I was able to print for the first time, of course this old machine was Based on a 5 bit code and was unable to print the full ASCII set.

My wife banned the noisy monster from the house and I relocated it to the garage. I have fond memories of the old computers including the Apple IIe which led my son and I to set up a bulletin board called Telegraph road which was part of Fido, who said email was something new ! This BB ran on the IIe with a Sider10meg hard drive that cost around $1500 a lot of money in the 80's and a lot of explaining to the wife.

Unfortunately I no longer have the same enthusiasm for computers, they have become just another tool, but then again I could not imagine life without them.

13-May-2010 Don McKenzie wrote:

Trevor gave me permission to post his email on this page. Trevor has beaten me to the punch with the earliest serial number in Australia, but I like to think I ordered and received mine first, as it was on order for several months before the first shipment arrived in Australia. Well, at least, we appear to be the first. Just sorry I lost the original receipt from March 1978. :-)

I placed my order months ahead of time and patiently awaited its arrival.

I began my journey with a WWII Baudot Teletype, eventually transitioning to a Siemens model I acquired during my tenure at the TAB (ATL). Yes, I had to engineer an interface for it. I shared a chuckle about the Baudot. My daughter, recalled how its carriage return would shake the house, sounding more like a cement mixer than a printer. Nowadays, I view computers as mere tools and harbor no desire to delve into hardware matters.

17-Jun-2011 Ian Mavric wrote:

Hi Don, I read your Australia's first PC page with interest and think I have a Model 1 which I might have purchased before you and Trevors.

See pictures attached, I bought 26-1006D serial number 009911 in 1978. To give validity to this (I've lost my original receipt) my monitor has Mfd Dec 1977 on the back of it (picture to follow on the weekend).

Timeline: 1978: Purchased the Model 1, then the EI and disk drives in 1979, a double density kit in 1982, and a 5Mb hard drive in 1983.

Modifications: Yes over the years I did quite a few. The main one is 512K Ram upgrade from Anitek (you can see the stacked 256K Rams and satellite bank-switching board) which enabled me to run LeScript with a huge buffer big enough to hold me thesis in one document. I replaced the keyboard cable with one which unplugs, and did the lower-case mod from Dennis Bathory-Kitsz Custom TRS-80 book and what-do-you-know the computer has a flying lowercase 'a' and no lowercase descenders. I also moved the reset button to the back of the machine where its easier to press and installed a Smart-watch real time clock because I was sick of typing the date and time every time I booted up. To make the system robust I installed Eap Co Gold plug 80s and the computer was just about bullet-proof. I still use it to make disks for my TRS-80 support hobby / cottage business.

Ian's Web Site

I just checked Ian's serial number and found that it is a later version and model that has the short keypad, Level II Rom and 16K Ram. It is the Catalog number that needs to be checked first.
Sorry Ian, it is somewhat later than mine. Cheers Don...

Check Serial Number

The other potential first PC claims

Art Clarke's units flown in via the us air force, if i use the term "sold in Australia", then regardless of proof or not, I have now discounted these. They have gone to heaven also.

Ian Mavric's is clearly a later model as the serial number and model indicates.

Trevor Moore may have been a contender, but I have been unable to contact him these days. I would like to think that if I had my unit on several months back order, that mine will (arguably) be the first sold in Australia.

Footnote

I've received some nice feedback recently and wanted to highlight one particular message. Thank you to everyone who has supported me over the years. I truly appreciate it.

Don...

29-May-2024 Geoff Watts

On 29/05/2024 7:26 pm, Geoff Watts wrote: Don,

I watched Dave's video today, and it reminded me that years ago (maybe very early 00s) I invested in a Simmstick or two, and was able to figure out how to build a pretty basic motorsport race timing system which I managed to sell to a Perth motorsport venue - which was a mixed blessing as they were always suspicious when I finished with a good time!
EEVblog 1619 - Video Mailbag: Featuring Don McKenzie ▶
That sparked something (entrepreneurship, tech, a combination of the two), and soon after I moved to London to co-found a software business with my wife, which was quite successful.

I also recall reading a lot of projects you designed in Silicon Chip.

Thank you for pushing technology forward in Australia, which I wish was more of a focus here than digging things out of the ground, and for inspiring me in my career.

Regards, Geoff Watts

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