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2S1P - Dual Serial/Single EPP Parallel Interface
The ECB 2S1P (or SPP for short) board provides two RS-232 level serial interfaces and a single PC/AT-compatible Centronics parallel port using the Texas Instruments TL16C552 multiport interface chip.
The ECB 2S1P board provides two 8250/16C550 similar serial interfaces (which is clocked at 1.8432mhz to provide common baud rates from 300 to 115,200) and a single PC/AT-EPP compatible parallel printer port using the TL16C552B PLCC chip and related level shifters. Two TTL-level headers are provoded for those wanting to use USB TTL interfaces directly.
The board was developed primarily for and tested for use with the SBC-188 80C188-based processor board, but it should work with other boards. The SBC-188 BIOS has been modified to enable MS-DOS to use this board as standard COM/LPT ports (albeit at non-standard port addresses).
As a point of note, the board is NOT compatible with the ST16C552 due to a different pin arrangement.
None in version 1.0-001 (the first production run).