Hack Chat Transcript, Part 2

A event log for Retrocomputing for the Masses Hack Chat

Spencer Owen and the RC2014

lutetiumLutetium 05/29/2019 at 20:030 Comments

AlanH12:24 PM
LOL It's not Western Digital.. It's Western Design Center

Linker300012:24 PM
Western Digital is the storage Co. It's Western Design Center ;-)

EtchedPixels12:24 PM
(and 6502, 6809, 68000)

EtchedPixels12:24 PM
(and 8085)

Linker300012:24 PM
(Used to work for Western Digital!)

Gregory Nutt12:24 PM
Right, Western Design Center.

Kevin12:25 PM
@Bil Herd oh, yes. The 6845 and 6847. Love those devices.

spencer12:25 PM
@epooch Tindie has been absolutely perfect for me. In fact, if it wasn't for the Tindie platform, I think i'd probably still be a network engineer!

Lex Landa12:25 PM
@Kevin I've heard of the 6845, but what's a 6847?

Bil Herd12:25 PM
Or as we call WDC the BMC, (Bill Mench Company)

Bil Herd12:26 PM
6847 was a composite NTSC video chip, it didn't get as much airtime but really made you drool in the days of TVs as mnitors.

Lex Landa12:26 PM
@Kevin I am familiar with the 6845 from my BBC Micro days..

Kevin12:26 PM
I also have my own 68000 CPU board done quite a few years ago. My design but a friend of mine wired it up for me (point to point). It runs at 8MHz. I've finally bought a 68B50 that will allow me to run the CPU at 10MHz.

Rudranand Sahu12:26 PM
What would you recommend or advice for implementing a CPU on an FPGA for the first time?

marblypup12:26 PM
@marten Awesome! It looks a bit like my Z280 board except that I turned the Z280 through 45 degrees. The result is so ugly I call it the Coyote280 :-)

Lex Landa12:26 PM
@Bil Ah.. that's why - we're in PAL over here. (UK)

spencer12:26 PM
The really nice thing about the modular nature of the RC2014 though, is the community have really taken it to heart, and started designing their own modules for it. There's now well over 100 boards out there which were designed to fit the RC2014 ecosystem :-)

19-rsn-00712:27 PM
MC6847 VDU was in the acond atom as well wasn't it?

AlanH12:27 PM
@Rudranand Sahu start from scratch

EtchedPixels12:27 PM
19: and the Tandy MC10, Dragon 32/64, COCO, COCO2

Kevin12:27 PM
@spencer I like the modular design you came up with for the RC2014. I also noticed the adapter for a Pi. :)

Bil Herd12:27 PM is where I go for existiing CPU in FPGA cores

Linker300012:27 PM
@spencer is the RC2014 your sole biz or do you do other things too?

marblypup12:27 PM
I've got a book about old cathode ray tube controllers, inc. 6845.

Bil Herd12:27 PM
@Lex Landa PAL didn't look good even when set for the right mode/clock

AlanH12:27 PM
Three things every engineer should do: grow their own transistor, implement a CPU at an RTL level, and port a high level compiler to it

19-rsn-00712:28 PM
do you do much FPGA retro implentation @Bil Herd ?

spencer12:28 PM
@Kevin Thanks :-) Yes, the Pi Zero module was one of the first I made for it. It's the cheapest way to convert serial data in to HDMI :)

Kevin12:28 PM

Bil Herd12:28 PM
Put you link for the ecosystem. :)

EtchedPixels12:28 PM
@spencer what's the craziest rc2014 board you've sene

EtchedPixels12:28 PM

spencer12:29 PM
@Linker3000 For 3 years now the RC2014 has been my only source of income #LivingTheDream :-)

Lex Landa12:29 PM
@Bil Herd Yes, as I recall, the aspect ratio was a bit strange.

@AlanH - I've got a 1940's vintage germanium diode I plan to turn into a transistor. Does that count?

Bil Herd12:29 PM
ah SED or PERL (feels like Rodgers when he gets a flying money reference)

David Richards12:30 PM
Greetings, I bought an old 64 pin micro in a big ceramic and gold package recently. Hope to build it into something retro some day. Though I got it mainly to admire it looks.

spencer12:30 PM
Basic RC2014 Module specs are here;

Bil Herd12:30 PM
PAL had stripes, they never got the color clock phase inversion correct is my memory.

marblypup12:30 PM
@David Richards Do you know which it is?

Kevin12:30 PM
@spencer How long did the development take before you were felt it was ready for others to buy and use?

Gregory Nutt12:30 PM
@spencer You use bank switching with the large RAMs. How does that integrate with the software? Can you run an RTOS of some kind on it?

AlanH12:30 PM
*cough* RC2020 w/ a 68020 *cough*

Bil Herd12:30 PM
Ah the MMU question :)

19-rsn-00712:31 PM
I've recently started playing around with my terasic DE0-NANO that's a whole new level of programming and system design.

Took me a month just to get the basics started and working.

Marten Feldtmann12:31 PM
Well, there are at leat some RTOS source codes available for the Z180

Rudranand Sahu12:31 PM
Thank you @AlanH, BTW which compiler is most beginner friendly to be modified to add a new architechture?

19-rsn-00712:31 PM
a shift register and some leds shifting to right and when reaching the last bit shifting them back to the left

Kevin12:31 PM
I have three Xilinx FPGA boards. Easy to get the flashing LED going. FPGA's are a whole new ball game.

spencer12:31 PM
@EtchedPixels I don't think any of the modules have been particulaly crazy. But I did release this one a couple of years ago

Bil Herd12:31 PM
Check out the DE10-Nano, still cheap but Cyclone V and SOPC built in, I am looking at some midly heavy DSP with one.

Lex Landa12:32 PM
I wonder if that's why my Beeb keeps losing its colour, in composite..

AlanH12:32 PM
@Rudranand Sahu I've only done gcc which isn't simple, but there are a lot of existing examples

19-rsn-00712:32 PM
What I would love to do is design a 6502 sbc and once the realy thing is finished, see if I can implent the thing into my fpga

Bil Herd12:32 PM
@kevin But you can WRITE hardware!

marblypup12:32 PM
@spencer LOL@googly eye

David Richards12:32 PM
@marblypup Sure, its a soviet pdp11 clone.description: KM1801VM3 (KM1801BM3) - Soviet 16-bit PDP-11 CPU with own NMOS ASIC design (by Angstrem factory)

Kevin12:33 PM
hehe... the googley eye board would be a lot of fun if you could control the movement of the eye part from the 2014. :)

Ed Thierbach12:33 PM
@spencer So how many googly eye kits have you sold?

AlanH12:33 PM
Easier to fix bugs with a text editor rather than a soldering iron.. but something to be said for projects like rc2014

marblypup12:33 PM
@david Crikey! I don't think I've ever seen a Soviet IC!

spencer12:33 PM
@Gregory Nutt The bank switching on the 512k version is designed around Wayne Warthens OS Z-System, which is a modern efficient implementation of CP/M.

Bil Herd12:33 PM
@spencer forgive me for not knowing, do you make the design files available also?

spencer12:34 PM
@Ed Thierbach None. It was only available for 24 hours on April 1st :)

19-rsn-00712:34 PM
I have to disagree with you there @AlanH ..... I find it easier to fix stuff in hardware than in code

AlanH12:34 PM
I was referring to FPGAs

Kevin12:34 PM
@Bill Herd oh, I know. I have two Spartan 3 boards and one Spartan 6. I just haven't had a lot of time to sit down and do much with them yet. I did wire up 8 seven segment displays using charlieplexing and started driving them with one of my Partan boads.

Gregory Nutt12:34 PM
@19-rsn-007 Depends on the complexity of the code vs. the hardware

Rudranand Sahu12:35 PM
It depends, if it's on mass scale then it's easier in software

19-rsn-00712:35 PM
I know, but VHDL and verilog is new to me so fixing stuff in the code is harder for me at least

spencer12:35 PM
@Bil Herd I make everything available except for the Gerber files. I'm more than happy for people to copy the rest of the design, but because I don't release the gerbers, I don't call it Open Source

Kevin12:35 PM
Open Source but not Open Hardware.

AlanH12:36 PM
FPGAs can poison the retro-well.. once you add that spartan-6 USB-everything bus analyzer module to a project like the rc2014.. might as well do the whole thing in programmable logic

spencer12:36 PM
@19-rsn-007 My preference is to always fix things in hardware if I can too. That's because my software skills are lacking :)

Marten Feldtmann12:36 PM
Around the RC2014 there are so many other implementations of CPU boards, motherboards - that actually its ok, that Spencer has not released the sources.

Bil Herd12:37 PM
@kevin Every example program you try is worthwhile. Just get used to turning things out from beginning to end and then also learn to simulate.

19-rsn-00712:37 PM
hehe I know that problem @spencer :)

marblypup12:37 PM
@AlanH Interesting view... I was thinking of adding a graphics board to my 68010, based on an FPGA.

Kevin12:37 PM
Doing both hardware and software is fun. You get to decide when to use hardware and when to use software for some part of a project.

Peabody192912:37 PM

David Richards12:37 PM
I've been experimenting with vhdl, its hard to move away from thinking sequential program logic to parallel logic.

Peabody192912:38 PM

Peabody192912:38 PM
One of the great things about RC2014 is the ability to "Design and Build Your Own". I went from the original RC2014 kit to a Z180 compatible RC2014 system of my own design. RC2014 provides the framework to make them compatible.

Marten Feldtmann12:38 PM
The FPGA is a nice add on for creating hardware items not available any more ... especially video stuff

Kevin12:38 PM
Hm... I can't seem to find Bill Herd in the list to reply to him properly.

spencer12:38 PM
@Peabody1929 That's a pretty little RC2014 :)

AlanH12:38 PM
@marblypup go woz old-school first and try it with a discrete design - maybe even with a 6845.. then cheat if you have to

@kevin - try @Bil Herd - one L

Bil Herd12:39 PM
@David Richards VHDL is usually a little harder to pick up for newcomers than Verilog. With that said the best programmer I saw programmed using the same casting protections in VHDL (where you pre-define the heck out of everything) only in Verilog

marblypup12:39 PM
@alanh Well.. I'm aiming for 640x480x8 bits, using megabit VRAMs... 6845 a bit too primitive!

Kevin12:39 PM
@Bill Herd, yes. Using an FPGA to control multiplexed LED displays is a step up from flashing a single LED. It was a good way to start getting in to something more complex. The charlieplexed display can even be used for debugging FPGA projects as it can be used for text output using a 7 segment based alphabet.

EtchedPixels12:39 PM

19-rsn-00712:39 PM
@David Richards , yeah learning yourself to think different when working the same way to years is a pain...but the satisfying felling when things are working is great

EtchedPixels12:39 PM
It gets to be an addiction 8)

19-rsn-00712:40 PM
and in the end all worth it

Marcel van Kervinck joined  the room.12:40 PM

AlanH12:40 PM
@spencer are there any case designs floating around?

Kevin12:40 PM
I read up on VHDL and Verilog. Based on what I read I felt that VHDL was the better language so I've been starting to use it even though my part of the world has Verilog as king.

spencer12:40 PM
I am always intrigued to see what other people build for their RC2014. Everyone seems to come up with great ideas and awesome looking machines.

Andrew Lindsay12:40 PM
@AlanH there are lasercut designs to sandwich the backplane

Linker300012:40 PM
@EtchedPixels You could sleep on that thing!

Bil Herd12:40 PM
Some day a job opportunity may arise because of something you have played with in your spare time.

Kevin12:40 PM
/me nods

EtchedPixels12:40 PM
@linker3000 the cat does

David Richards12:41 PM
Hi, yes, multiplexed display was the first thing I had to to on my system. trial by fire, very rewarding when it worked.