SYNERTEK MBC020 Video Output and More RAM

After figuring out the location of the video output on the MBC020's P4 connector (pin 20), I noticed that the video and ground signals are also connected to some large through-hole pads nearby. These may be solder points for a video coax cable, or some sort of connector.

I hoped to avoid soldering directly onto the board, so I first tried some "9mm Through-Hole Loop Test Points". These fit nicely in the holes in the board, but I struggled to get them connected to a coax video cable. Withe the added weight of a cable, they pulled out too easily and were generally awkward to solder and secure.

The obvious choice for this was a PCB mount RCA/phono jack for the composite video. Unfortunately, there was just no clearance on the front of the board since an IC and the board ejector interferred with the placement. Only after my failure with the test points did I realize that, after bending up one of the ground legs, there was plenty of space on the back of the board:

With the RCA/phono jack inserted, I booted it up. The video displays "SE" until the serial connection is made, and then is shows the exact same information as the terminal. Unfortunately, some testing uncovered that the top 1/4-1/2 of the screen has some apparent tearing and sync issues which improve progressively down the screen. The bottom 1/2 of the screen is very clear 80 column output. I am not sure why this is happening, but I would assume it is a damaged component on the board. Moving around the video jack to get a better connection did not improve the video quality. Since this monitor has proven to be compatible with many vintage video devices, if there is a compatibility problem I think it must be the board that is way out of spec.

So, video is almost working.

Next, I tried adding the unmodified Mikul 6218 board with extra RAM installed in place of the usual ROMs. Although I did not test the I/O, the RAM addition worked great! Using SERVOMON commands, I was able to edit memory areas that were previously unassigned. This confirms my belief that the Mikul 6218 is a really nice and reasonably priced memory board for a variety of EXORbus systems, especially because the memory sockets are very configurable for a variety of RAM and ROM chips.

Next time I will document the memory map further and check out the keyboard connection to try to make it a complete terminal!

CMS 9619 Drivewire Boot to NitrOS-9

I finally got drivewire running on the CMS 9619 SBC. As a result, I managed to complete the bootup and have a virtual disk! Source code available on github.

Demo Video of a2usbdsk in a Apple II build and deployment pipeline

The build pipeline is an update of Jeremy Rand’s Apple2BuildPipline based on Quinn Dunki’s project of the same name. Using this allowed me to stop reinventing the wheel and focus on finishing coding my a2usbdsk tool. Definitely check those projects!

RC 2015/01 Epilogue

A member of 68kmla.org was nice enough to test out ElWhip on a real Macintosh 128K: ...and a 512K.

First time getting a REAL Macintosh 128K on the internet. So great!

ElWhip 0.06 Download and Video Finale

ElWhip Webserver 0.06 Download now available.

RetroChallenge 2015/01 Summary:

• Repaired video on my Macintosh
• Compiled and modified lwIP Web server to run on Macintosh
• Wireless logging
• Modified Mini vMac to run virtual serial ports on PPC Mac OS X
• Lubricated all of my old Mac disk drives
• First web server to run on Macintosh 512K
• First PPP connection, TCP/IP stack, and web server to run on a (virtual) Macintosh 128K

So, a ton of work, but a success, even though it could still use a little work to clean up a few things. Thirty-one years after its introduction, the original Macintosh is finally on the web! This was a great experience and I was able to learn a little too much about the Macintosh Toolbox. This was a bigger project than I expected, and it took a lot of tweaking to get everything running in 128K. Thanks for the motivation RetroChallenge!

RetroChallenge 2014WW Video Finale

Success and Video Update

Got it! Hitting the enter key rather than clicking the mouse on the dialog boxes makes the connection. That's either a timing or mouse port serial interrupt issue. Oddly, the return key doesn't do anything. I have TCP/IP networking on my original (modified) Macintosh! I think the memory use is low enough, it should work on a real 128K Macintosh. Is it pronounced "El whip" or "l.w. I.P."? I like the Mexican flair of El Whip! (Actually, it's pronounced "lightweight IP" - boring…)

Good Enough

Finding ways to reduce the latency between sector transfers is getting tougher and tougher. The UM232H writes and reads packets with low latency, but when it goes back and forth between the two, significant delays occur.

I used some source code from MAME to load the different disk image formats. I had to make extensive edits to get it working outside of MAME though. ProDos and DOS 3.3 disks work fine. Most game disk images I have tried are working:

• Moonpatrol
• Choplifter
• Ms. PacMan
• Bouncing Kumungas!
• Jungle Hunt
• Donkey Kong
• Mario Bros.

Still no Karateka though.
I think it is 'good enough' for now. A computer faster than my PowerBook G4 might help. Here is video of my progress:



The LCD viewfinder is broken on the camera, so I missed my shot a few times.

I added a logging level option to the command arguments after I shot this video. I can set the verbosity at run time instead of needing to re-compile. I am working on my schematic today to make sure it is up to date.

I received my surface mount resistors for the IIgs from China earlier this week. I only needed one of each, but I could only buy 100 of each. Anybody need 198 surface mount resistors?