test-drb

test-drb@ccmp.vtda.org

101090 discussions

by mike＠fenz.net

A question for someone with specialist knowledge in 6809s. I work on pinball machines a lot, and the 68B09E is a commonly used CPU. Unfortunately, it's getting harder to find 68B09Es (though by no means impossible quite yet). It seems that most of them on eBay are counterfeits; the last lot I bought were all fake, marked Japan on the front, but China on the back. They looked very convincing, with the markings etched very nicely, rather than printed. Unfortunately, they didn't work. Overall, it looks like getting 68B09Es is becoming harder, and I'm wondering if there's some alternative. I spent a while looking over the datasheets of the 68B09 as compared to the 68B09E. It's obvious that there's some difference in the way the timing works, but I haven't been able to come to any firm conclusions what the exact difference is, and what purpose it serves. The best I can do is that it's related to synchronization with some external devices. So - can anyone explain the difference, in terms that aren't too hard to understand? And - is there any hope of modifying a machine that would normally require a 68B09E to be able to use a 68B09?

12 years, 1 month

6809 vs. 6809E

by mike＠fenz.net

Now there's a suggestion that has my attention. I have thought about this before, but I have no FPGA experience at all, and wouldn't know how to start. If it's just a matter of taking a a core model, setting it up for the target device (assign pins etc.), and writing it, I'm sure I could cope with that. But I suspect I'm simplifying things greatly there. It'd also depend on whether a 6809 model would make it obvious how to get at the LIC and TSC signals. Maybe there's someone on this list who I can pester with questions? On 2/07/2014 3:19 p.m., David Riley wrote: > My advice, faced with a dwindling supply of pulls (you > used to be able to buy 'em by the bushel from Jameco) > is to consider making a drop-in replacement using > one of the many VHDL/Verilog models now available and > a cheap, tiny FPGA like the MAX II (which Altera likes to > call a CPLD, even though it really isn't) mounted on a > DIP carrier board. > > I wonder if there's a market in that for the arcade community... > > - Dave

12 years, 1 month

DECwriter III LA120 ribbons?

by bob＠jfcl.com

Does anybody have a source or replacement for LA120 DECwriter III ribbons? I've actually got about 8 "new old stock" ones, still shrink wrapped, but all that I've tried are pretty much dried out despite the shrink wrap. They barely make a mark on the paper, even with the little print impression lever cranked all the way up. Thanks, Bob

12 years, 1 month

VCF East 10 aka "VCFeX"

by evan＠snarc.net

Mark your calendars: VCF East 10.0, aka "VCFeX", will be April 17-19 next year.

12 years, 1 month

6809 vs. 6809E

by mike＠fenz.net

I don't think the requirement is there yet. 68B09Es are still available; they're getting a bit more expensive, but you can still pick them up for under $10 without too much trouble. They don't fail that often either, failures usually seem to be in the RAM, 6821s, sockets etc. When you say 'use a small FPGA development board', do you mean to emulate the entire controller board, or just the CPU? Just curious what you had in mind. On 2/07/2014 3:41 p.m., ben wrote: > I thought the arcade market would use a small FPGA development board. > Note small is relative here.

12 years, 1 month

6809 vs. 6809E

by mike＠fenz.net

Yep, I'm hoping that I might get away with a few adjustments on the clock side of things. It all depends on those signals that aren't brought out on the 6809. Will find out, hopefully tonight. On 2/07/2014 3:04 p.m., Brian L. Stuart wrote: > Without seeing the full design, I can't really say. However, I > encountered the whole issue when doing a 6809 SBC and did > end up converting what I had originally designed for 6809Es to > 6809. I did the second rev of the board with jumpers so you could > use either one. If none of the rest of the machine uses any of > the processor signals that are unique to the E part, then making > the changes to use a 6809 aren't too major. How feasable it is > in practice really depends on the rest of the design. > > BLS

12 years, 1 month

6809 vs. 6809E

by mike＠fenz.net

A nice simple explanation - thanks! So 34 and 35 are effectively output on the 6809, and input on the 6809E. No problem there, but it looks like LIC and TSC (38 and 39) not being available on the 6809 would be an issue. I might take a look over a few designs (Williams WPC, Data East audio processor, Williams audio processor) and see if they make use of those. I expect they do... On 2/07/2014 2:56 p.m., Eric Smith wrote: > The 68x09 (no E suffix) has an internal crystal oscillator circuit (pins 38 and 39) and generates the required quadrature clock (E and Q, pins 34 and 35). The 68x09E requires an external quadrature clock input (E and Q, pins 34 and 35), and uses pins 38 and 39 for other functions (LIC and TSC, respectively).

12 years, 1 month

9-Track Tape Questions

by michael.99.thompson＠gmail.com

> From: healyzh at aracnet.com > To: cctalk at classiccmp.org > Cc: > Date: Mon, 30 Jun 2014 11:39:35 -0700 > Subject: 9-Track Tape Questions > Asking for a friend... > > Is it possible to still get new BOT markers? If so, does anyone know a > source? Can markers from Audio tapes be used? > > Also, does anyone have a list of common error codes from 9-Track tape drives? > > Zane I bought a roll of audio ones here: http://usrecordingmedia.com/netmerefoset.html They work find on the 7-track TU20 at the RICM. -- Michael Thompson

12 years, 1 month

Classic Computer Gaming Communities

by jam＠synthetica.org

Hi Everyone, I know this is slightly off topic, but I'm wondering if anyone knows of, or is a member of, any mailing lists that are related to computer games, preferably older, but with the same quality as this list. Thanks for your time and happy hacking. - Josh

12 years, 1 month

Fwd: [comp.sys.cdc] Re: Chippewa Labs Rollcall, June-December 1964

by legalize＠xmission.com

This message has been forwarded from Usenet. To reply to the original author, use the email address from the forwarded message. Date: Mon, 30 Jun 2014 14:01:00 -0700 (PDT) Groups: comp.sys.cdc From: mmccrossen at arletak8.net Subject: Re: Chippewa Labs Rollcall, June-December 1964 Re: <3cc1ca19_2 at news.iglou.com> Id: <f5640b38-afa0-42a6-a760-e121353fbd61 at googlegroups.com> ======== My dad, Garner McCrossen was the main FORTRAN programmer from what I've been to ld (other than Seymour). I had lunch with Les Davis, Edna Bunn, and Verene Cray last year (2013) and Les is a gold mine of early Cray history. Please do not use the email address above. pdxmelinda @ comcast.net is best.

12 years, 1 month

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

1998

1997

test-drb