Table of Contents Schematic Diagram DRAM Circuits Ports & Connectors SCSI and Parallel Interface Circuits Serial Interface Circuits ROM Circuits Component Placement Diagram Parts List Integrated Circuit and Logic Data 74LS20 U2, U12, U24 74LS175 U3. U4 74LS138 7407 6551 ACIA U7, U10 74LS04 74LS02...
The MIO has 3 basic addressing areas: 1) ACIA at $D1C0-$D1DF, 2) MIO Latches at $D1E0- $D1FF, and 3) 256 bytes of RAM at $D600-$D6FF. Note that the ACIA and MIO latches are not fully decoded; both contain 4 read/write registers, but each register has 7 shadows. Tables 5-1 through 5- 3 briefly describes the MIO registers.
$D1FF B 1 = R:/P: Handler ROM B = Printer BUSY- IRQ B 1 = Seg 1 of setup MENU B = MIO IRQ (from 6551 or All bits 0 disable the ROM. Printer BUSY- IRQ) $D1C0 Write ACIA transmit register.
Data Terminal Ready (DTR) Data terminal not ready (DTR false)*. Data terminal ready (DTR true). Note * The transmitter is disabled immediately. The receiver is disabled but will first complete receiving the byte in process. MIO Service Manual Page 60...
7 of $D1E2 is set ('1') and the printer BUSY is false ('0'). Bit 4 of $D1E3 is the general IRQ flag from the MIO (a 1 indicates that IRQ- is true). If bit 3 is also set, then the IRQ- is caused by the printer.
Software Description In order for the MIO to perform its multitude of tasks, one full page of memory has been allocated for general operating variables and configuration parameters. Two other pages have been reserved for "R:" handler input and output buffers, and the rest of memory (up to 4093 pages) can be used as RAM drives and a printer buffer through the MIO ROM.
+0: Number cylinders on drive (MSB,LSB) +2: Numer heads on hard drive +3: Cylinder to start reduced write current +5: Precompensation value (usually 0) +7: ECC burst length (usually $0B) Table 5-5. MIO Operating Variables Address Symbol Length Function of operating variable...
(via the DOS PRINT command and batch files). All the syntaxes use just "R:" for the device name since there is only one RS-232 port on the MIO. In fact, if you do use a port number (ex. "R2:"), it is simply ignored and treated the same as "R:".
STATUS command. If there were an error (DUMMY<>1), then BASIC would halt and give an error message (unless a TRAP was performed prior to the STATUS). The block mode STATUS (first syntax) returns a status history of the port (in FLAGS) and the state MIO Service Manual Page 66...
Dec Equiv Meaning When Bit is Set (1) DSR is true (ready) CTS is true (ready — Always true on MIO) CRX is true (ready) RCV is at MARK (Always Set on MIO) * Bits 6, 4, and 2 are simply copies of the next highest bit. In the 850 Interface, these bits would indicate a history (i.e.
(0 or 128) for the desired number of stop bits per word. Note that the word size is always 8 bits plus 1 or 2 stop bits; the MIO "R:" handler does not support smaller word sizes as did the Atari 850 interface.
"block mode", the statement returns the state of the handshake lines. This has no effect on the rest of the "R:" handler functioning or on the ACIA. It simply set a flag for the STATUS function. MIO Service Manual Page 69...
4 - DTR 1 - CRX 3 - XMT 2 - RCV 5 - GND 6 - DSR 7 - RTS 8 - CTS ¶ Frame — to the No connection to shield ¶ shield wire MIO Service Manual Page 70...
All handshaking lines are connected even though most applications would work with only XMT, RCV, and GND. The Toshiba printer is a DTE device and the MIO is also a DTE device. This requires the crossing of XMT and RCV. Be sure to check your printer manual for pin out as most printer connectors will vary.
Beta xxx SCSI (cartridge drive xxMb) Rodime RO650 SCSI (includes drive 10Mb) RO652 SCSI (includes drive 20Mb) Seagate ST225N SCSI (includes drive 20Mb) Western Digital WD1002-SHD SASI ST506/412 XEBEC 1410 SASI ST506/412 1410A SASI ST506/412 MIO Service Manual Page 72...