RCONN@simtel20.ARPA (08/31/84)
From: Richard Conn <RCONN@simtel20.ARPA> Mike, I use the Ampro Little Board within an Ampro Bookshelf Computer. This computer consists of the little board, two 790K 5 1/4" minifloppies, powersupply, and case and connectors. I have found the little board to be exceptionally reliable. It has never glitched or provided any problems. Physically, it is quite small -- small enough to fit on the back of a 5 1/4" minifloppy drive. It includes a Z80 micro running at 4MHz, 64K RAM (dynamic, 8 bits), one Z80-DART (provides two serial ports, RS-232C, with the normal complement of handshaking - DTR, CTS, etc - and one port can go up to 38,400 baud while the other goes up to 9600 baud), one parallel I/O port (bidirectional), one Z80-CTC counter-timer chip (only one channel out of the four is free for general use - the other three are used for clocking the DART and the disk controller), and one 179x (1793, I think) floppy disk controller chip. The disks are quite fast. I will be running some metrics on them soon, but as a rough estimate I would say they rival my 8" DSSD disks in speed. The unit I use has two 96 TPI drives, giving 790K storage per disk, and it can read and write several different 96 TPI formats. There is also a program which enables it to read (but not write) 48 TPI - I understand that writing 48 TPI on a 96 TPI drive is not physically possible. There is an outgoing connector which can be used to tag on two more drives (either 96 or 48 TPI, so you can obtain 48 TPI compatability), and I have heard that Ampro now has a Winchester (10M) running off the external disk connector. If you have 48 TPI compatability, there are about 20 different disk formats you can read or write, such as Heath, IBM-PC (CPM-86), etc. All must be CP/M compatable. In the way of software, a scaled-down ZCPR3 comes with it. Running on this is FRIENDLY (a VFILER/MENU/other utility), T/MAKER III, and a number of machine-specific programs for configuring the Ampro under software control. Some PD software, like MDM740 and source to the proper overlay, is also included (MDM740 is already installed). Echelon will sell you the standard ZCPR3 package, fully installed for the Ampro, for $39. The version of the Ampro Bookshelf I have been describing (with two 790K minifloppies) runs for $1500. My main use for the Ampro is as a slave off of my main system. I can redirect I/O so that the Ampro can record screen displays for me with no overhead on the main system, and I am in the process of adding a printer spooler and background batch processor to the Ampro. I occasionally use the Ampro in stand-alone mode, like for talks (because it is very portable), but most of the time it is a slave. At 790K, it offers a lot of spooling space and recording space. Some day I plan to experiment with distributed systems using the Ampro and my main machine. Rick