According to Carlos G Mendioroz, who wrote these programs:
Ok, code is not clean at all, but with a little help it should be understandable...
It read the raw dump as 0/1 for sample and makes run length codes of periods (at rising edges). There is a class for doing the timing (finding the first long preamble and then resynching at preambles) and then some utility methods to follow the block structure, decode the gcr 4/5 and calculate CRC.
The main trick ended being variating the timing when an exception occurs and retry decoding a block. it tries -2, -1, +1 and +2 reference periods, which change the 0/1/2 run length boundaries.
Let me know if you need help understanding it. There is no output yet, but having a good CRC kind of proves the decoding of the block was ok (and the block id matching :)
Sunday, April 22, 2018
Sunday, April 15, 2018
It's not directly QIC Reader related, but it is a VERY useful tool!
Latest downloads should be at http://www.autoelectric.cn/en/tl866_main.html
Download install file MiniPro_setup670.exe
Supported Chips List:
Wednesday, May 11, 2016
Click here to download the .logicdata file that I display in my video above.
I see in the following doc, that there are a number of different "preformatted" QIC cartridges of this era:
Compatibility and Competitive
Cross Reference Information
Data Cartridge Tape Products
Looks to be a 3M thing, since these are all their model tapes, and this is their publication.
Monday, April 18, 2016
I've read a few tapes purportedly from the Zilog S8000 using a DEI drive, and a quick look at the data captures in the Saleae GUI appears to show an MFM format, but with the data block anatomy unknown at this time.
So that I can orient myself to the data pulses I see in these captures, I'm reviewing the
DEI (Data Electronics Incorporated) Series CMTD-3400S2 6400 BPI High Density Cartridge Magnetic Tape Drive Operation and Maintenance Manual
It is believed that this is the drive that these tapes were written with.
Here's what the beginning of the first block looks like: