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VintageTEK RAMPACK: Difference between revisions
Added a functional description from the designer of the module
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[http://www.classiccmp.org/pipermail/cctech/2015-November/012710.html A short description by Micheal Cranford]: | |||
<blockquote> | |||
The purpose of the RAMPACK is to effectively replace the mag tape drive since the latter requires mag tape cartridges that are no longer made and the tension bands degrade over time and fail. The lack of functional mag tape cartridges can quite severely limit the usefulness of the 4051. Since the Tek museum cannot demo the 4051 very well due to the lack of reliable mag tape cartridges and any user created programs disappear with powering down, I decided to create the RAMPACK. I had actually started working on that decades ago when I was at Tek but at the time it was just for speeding up file manipulations and that RAMPACK was totally DRAM based. The new version in contrast is non-volatile and it holds far more data. | |||
Note that this is a plug-in ROM PACK and it does not require altering the mag tape drive or the 4051 computer in any way. The RAMPACK contains about 2MB of high reliability guaranteed 100+ years of data retention time flash memory, which totals to at least seven DC300A mag tape cartridges worth of data. In actual practice it will hold more than seven cartridges worth since the mag tape storage is inefficient with small files. As an example a DC600 cannot hold 256 files of minimal length (768 bytes) since each inter-file gap takes nearly 4 inches of tape. In contrast my RAMPACK can hold 511 files of 4KB each. | |||
You create and access RAMPACK files just like any other GBIP device on the 4051. Each RAMPACK has a unique IO address and multiple RAMPACKs can be installed at the same time. Simple examples include (the below assumes installation in the right rear slot in the back of the 4051): | |||
1. FIND @51:1 | |||
2. MARK @51:2,4096 | |||
MARK 2 files that are 4KB byte long. Note that marked files will | |||
always be multiples of 4KB in size, and the MARK command will | |||
automatically pick the smallest multiple of 4KB that includes the | |||
user specified size. | |||
3. SAVE @51: | |||
4. FIND @51:1 | |||
5. OLD @51: | |||
6. FIND @51:2 | |||
7. PRINT @51:A, A$ | |||
8. CLOSE | |||
9. FIND @51:2 | |||
10. INPUT @51:A,A$ | |||
11. Etc. | |||
There are about 23 functions that support ASCII program and ASCII or BINARY data files, write protecting arbitrary files, SAVE and OLD/APPEND for SECRET programs. listing the details about all of the RAMPACK files (the equivalent of TLIST), checking the current file status, naming each file (names can be up to 24 ASCII characters long) and a whole bunch more. The RAMPACK can also update its own firmware.</blockquote> | |||