Serial Board May 31, 2015

Transcription

1 Serial Board May, 0 The Apple Serial board uses a ACIA. The addressing for this board has been designed to mimic the Apple 680 PIA at the $D0X locations and still provide full access to the in the $D00X space. The 680 is disabled during Serial Board accesses using the VMA mod where the VMA line short to + is replaced by a resistor and capacitor so the VMA line can become active. Using this modification the 680 can be disabled on a cycle by cycle basis by pulling down the VMA line and the Serial board function can be enabled in its place. The board has no on board firmware and no additional software is needed for the boards operation.the board is compatible with all Apple software. Figure is a photo of the finished board. Figure Table shows the valid addresses on the Serial board and the suggested addresses to be used.. Table shows where the addresses map into the space. Table shows the corresponding Apple locations so that with the remapping the Serial board has exactly the same register mapping as the Apple 680. Note that on the reads from $D0 and $D0 the appropriate bit is remapped to provide the proper ready bits to match the Apple Keyboard and Display locations. Therefore when the VMA is pulled disabling the 680, the Serial board provides an exact substitution. This means that the serial board operates exactly like the 680 and there are no software changes of any kind to use the serial board. On the other hand the full set of Serial Board registers are still available at locations $D00 to $D00. Page

2 Apple Serial Board Description Full Binary Address x = don t care Suggested Address to Use 0 xxxx xxx0 x0x0 $D00 0 xxxx xxx0 x0x $D00 0 xxxx xxx0 xx0 $D00 0 xxxx xxx0 xx $D00 0 xxxx xxx x0x0 $D00 0 xxxx xxx x0x $D0 0 xxxx xxx xx0 $D0 0 xxxx xxx xx $D0 Table The VMA line action from the serial board can be disabled by removing the jumper labeled VMA on the board. The address locations at $D00 to $D00 could still be used since the 680 is disabled at these addresses but the 680 would not be disabled at locations $D00 to $D0. This makes the Serial board useable even if there is no VMA mod made, however, substitution could not be used. Attached is a schematic of the Serial Board. One circuit of note is Q and Q that form a circuit that will detect a Break sent from a remote device and will reset the Apple when a Break is received. This permits remotely managing the Apple so that the Apple could be made into a dial up computer and if the Apple requires a reset it can be sent. This function can be disabled by removing the jumper labeled RESET from the board. When using the Serial Board with a Mac using the CoolTerm program and a Keyspan 9HS we observed that the use of the high bit of the characters being a caused some issues. The CoolTerm expects the high bit to be a zero and sends the characters with the high bit a zero. This caused the CoolTerm to recognize the incoming characters as special characters when in 8 bit transmission mode and the characters with the high bit cleared caused the Apple to not respond properly to the incoming keystrokes. J9 and J0 labeled Tx and Rx were added to optionally force the high bit to be a one as needed for general use. This change only affects the $D0x addresses so that custom programs using the $D00x space are not affected. The exact behavior is described in Table. Page

3 Apple Serial Board Description Write Read Switch Status Address VMA Tx Jumper VMA Rx Jumper On Fixed On Fixed Don t Care D00 Write Transmit Data Read Receive Data Don t Care D00 Programmed Reset (Data don t care ) Read Status Don t Care D00 Write Command Read Command Don t Care D00 Write Control Read Control KBD ON D00 Disabled Open N/A N/A Read Receive Data KBD ON D0 Disabled Open N/A N/A Read Status Bit Bit KBD OFF D00 Disabled Open N/A N/A Disabled Open N/A N/A KBD OFF D0 Disabled Open N/A N/A Disabled Open N/A N/A DSP ON D0 Write Transmit Data (Not ) Read Status (Not Bit ) (Not Bit ) DSP OFF D0 Disabled Open N/A N/A Disabled Open N/A N/A Don t Care D0 Disabled Open N/A N/A Disabled Open N/A N/A Table Page

4 Apple Serial Board Description Address Write Read D00X D00 D0 680 Inactive KBD Data KBD Control = Ready D0 DSP Data DSP Status = 0 Ready D0 DSP Control Table Table shows the serial pinout on the board and the mapping for various RJ to DB configurations. Signal Serial Bd RJ DB9 Adapter DB9 Xover DB Adapter DB Xover Clear To Send (CTS) Data Set Read (DSR) + Carrier Detect (DCD) Receive Data (RXD) 6 Gnd 7 7 Gnd 7 7 Transmit Data (TXD) Data Terminal Ready (DTR) Request To Send (RTS) 7 8 Table Adapter Pinouts Page

5 Apple VMA Signal Activation The VMA signal is a signal needed for the 6800 microcomputer but is not used on the 60, the pin is a no-connect on the 60 and a shorting connection area is provided on the Apple board to short it to. The signal is of interest because it is available on the I/O connector. The signal goes to the NAND gate at B where it is combined with refresh and the result goes to the 7 decoder disable pins 8 and 9 disabling all the decoded addresses whenever there is either a refresh or the VMA is low. The signal also goes to a chip select pin on the 680 PIA which is redundant because the 680 is disabled whenever the decoder is disabled. The VMA signal can be restored to availability again by replacing the short at approximately A8 labelled 60 with a pull up resistor. A 00 ohm resistor in parallel with a 00 pf capacitor should be used, the capacitor controls some crosstalk that has been observed on the signal. When small surface mount parts such as the 00 parts shown in Figure are used the alteration is nearly invisible. An alternate implementation is to remove the short at the location and put the added parts under the board between pins and 8 of the 60 at location A7 or pins and of the DIP at location B. The capacitor must be connected to the rail instead of GND. Figure This modification makes available a signal on the peripheral connector that can be used to disable anything accessed using the decoder on a cycle by cycle basis. This includes the 680 PIA, all on board RAM, the boot ROM and any peripheral using the R, S, or T signals. This permits a peripheral to perform hardware substitution for any of those functions. Page

6 Serial Board Testing For testing the Serial Board the Apple or Clone must have the VMA mod performed meaning that the short on the Apple labeled 60 near the K resistors and near pin of the 0 pin socket at A7 should be removed and replaced by a 00pf Capacitor and 00Ω resistor across the terminals with surface mount parts or between pins and 8 of the 60 at location A7 or pins and of the DIP at location B. The Serial board should be configured as shown in Figure and plugged onto the PC board connector of the Apple or can be plugged into an expansion slot of a known good Expansion Board configured as shown in Figure. Figure Figure Power on the Apple and verify that the system will reset and that the Keyboard and Display work normally. Type D00:8B 96 Page 6

7 Serial Board Testing Verify that the write was successful by reading locations D00 and D00. This will set the Serial Card to be 00 baud, 8 bit, stop bits, parity disabled. Connect the serial board to an RS source that is configured as a dumb terminal. The Keyboard and Display should still work normally. Turn ON the KBD switch as shown in Figure. Figure Now typing on the terminal device should be active and the Apple display should remain active while the Apple keyboard should not be active. Turn OFF the KBD switch and turn ON the DSP switch as shown in Figure. Figure Now the display on the terminal device should be active and the Apple Keyboard should be active while the Apple display should not be active. Now turn ON the KBD switch so that both switches are ON as shown in Figure 6. Figure 6 Now both the display and keyboard on the terminal device should be active and the display and keyboard on the Apple disabled. Send a Break signal from the dumb terminal and see that the Apple is reset. The reset will take place regardless of the KBD and DSP switch settings on the Apple Serial Card. Page 7

8 Serial Board Testing USING AN APPLE II AND SUPER SERIAL CARD AS A DUMB TERMINAL Install an Apple II Super Serial Card into the Apple II with the Super Serial Card configured as shown in Figure 7. This will set the data rate at 00 baud and match all the settings on the Apple Serial card. Connect the Apple serial card using an RJ to DB adapter such as the CUI AMK-0 wired as a DB Adapter as shown in Table of the Apple Serial Board February 0 document. Figure 7 In this example it is assumed the Super Serial Card is in Slot. On the Apple II type ]IN# Type IN# to activate the Super Serial Card ] After the ] prompt type ctrl(a) APPLE SSC:T The Apple II will respond with APPLE SSC: then type T carraige return The SSC is now in Terminal Mode. To send a break signal again type ctrl(a) APPLE SSC:B The Apple II will respond with APPLE SSC: then type B carraige return The SSC will now send a Break Signal. If the Apple Serial card has the DSP switch ON then the Apple II screen will show _\ Page 8

9 Serial Board Testing USING A MAC WITH A KEYSPAN USA-9HS AND COOLTERM AS A DUMB TERMINAL Connect the Apple Serial card to the USA-9HS using an RJ to DB9 adapter such as the CUI AMK-000 wired as a DB9 Adapter as shown in Table of the Apple Serial Board February 0 document. Using the configuration file labeled CoolTerm Terminal attached the Mac will behave as a dumb Terminal. The Send Break command is under the Connections tab. If a Break is sent when the Apple Serial card has the DSP switch ON the response on the Mac screen will be..\ The CoolTerm Terminal file uses the font PrintChar as this is a match to the Apple and Apple II Fonts. This font is available from Page 9

10 Serial Board Auxiliary Documents C R R C u C8 0.u C7 0.u C6 0.u C 0.u C 0.u C 0.u C 0.u 0.u.K.K -V 7LS A B U8 +V K R R K 6 8 IN A OUT Y IN A OUT Y IN A OUT Y IN A U OUT Y IN B IN B IN B DSC88J TxD U 8 /DTR /RTS ACIA RxD 9 /CTS D0 D D D D D D6 D IN A IN A IN A IN A CNTL CNTL CNTL CNTL 7 OUT Y OUT Y OUT Y OUT Y 7 /DSR RS0 RS 6 /DCD 6 /IRQ CS0 /CS RxC R//W 8 GND E /RESET XTAL XTAL J PCB -V Z +V Y GND X GND A0 W A A V A A U A A6/0 T A7/ A8/ S A9/ A0/ R A/ A P A A N A 0 M T L DMA R /W K D0 D J D D H D D F D6 D7 E RDY D /IRQ VMA C /NMI BA B /RES A /RF R S J8 9 U7.C 8 7LS 0 6 U.C U 7LS0 X J MHz 8 +V GND U0 Vin ua79 -V R6 0.u C9 VIN U9 VOUT MC78LAC GND 0.u C C0 7LS0 U.A 9 U.D 8 7LS0 R7 0 RDY /IRQ /NMI /RES /RF 0 STB U6 A B DSC89J D0 Y D 6 W D D D D D6 D7 7HCT 7 9 C 0 0.u U7.D 7LS 0 U.E 7LS0 SPDT Toggle 7 9 G CO C Y C Y C G CO C C C 6 0 U7.B 7LS 6 U.A 6 7LS0 R K 7LS0 U.B Q C 7LS0 U.F u 8 U.B 7LS0 9 0 SPDT Toggle J PIN 0.6 Z -V Y +V R X GND W A0 V A GND A A AUGUST U A A 7 T A6/0 S A8/ A7/ A9/ 6 R A0/ A/ RJ Jack J CTS DSR RXD GND GND TXD DTR RTS P A A N A M 0 A S L T DMA 0 K R /W D0 9 J D D 8 H D D 7 F D D Q E D7 D C VMA B BA A MAX809 FJV0R LM80 U 7LS U U7.A U NC7SZ86 HDR X J0 FJV0R HDR X J9 R TXD DTR RTS RXD CTS DSR DCD K 0K 0K 0K 0K SERIAL BOARD REV Page 0

11 Serial Board Auxiliary Documents Page

12 Serial Board Auxiliary Documents Page

13 Serial Board Auxiliary Documents Page

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16 Serial Board Auxiliary Documents Serial Board Rev Parts List Designator Part Value Manufacturer Mfg Part No. Description C CAPACITOR 0.u 0. In Radial Monlythic C CAPACITOR 0.u 0. In Radial Monlythic C CAPACITOR 0.u 060 CAPACITOR C CAPACITOR 0.u 060 CAPACITOR C CAPACITOR 0.u 060 CAPACITOR C6 CAPACITOR 0.u 060 CAPACITOR C7 CAPACITOR 0.u 060 CAPACITOR C8 CAPACITOR 0.u 060 CAPACITOR C9 CAPACITOR 0.u 0. In Radial Monlythic C0 CAPACITOR 0.u 0. In Radial Monlythic C CAPACITOR u 0. In Radial Monlythic C CAPACITOR u 0. In Radial Monlythic C CAPACITOR 0.u 060 CAPACITOR J RJ Jack Molex RJ Jack J6 Card Connector PIN 0.6 EDAC Pin.6 Connector J7 HEADER X SAMTEC TSW-0-07-L-S X 0. In Header J8 HEADER X SAMTEC TSW-0-07-L-S X 0. In Header J9 HEADER X SAMTEC TSW-0-07-L-S X 0. In Header J0 HEADER X SAMTEC TSW-0-07-L-S X 0. In Header Q FJV0R Fairchild FJV0R SOT Q FJV0R Fairchild FJV0R SOT R RESISTOR KΩ 060 RESISTOR R RESISTOR KΩ 060 RESISTOR R RESISTOR.KΩ 060 RESISTOR R RESISTOR.KΩ 060 RESISTOR R6 RESISTOR 0Ω 060 RESISTOR R7 RESISTOR 0Ω 060 RESISTOR R RESISTOR KΩ 060 RESISTOR R RESISTOR KΩ 060 RESISTOR SW SPDT Toggle C&K T0MH9ABE SBDT TOGGLE POS SW SPDT Toggle C&K T0MH9ABE SBDT TOGGLE POS U ACIA 8 PIN 0.6 DIP U DSC88J TI DSC88J PIN DIP U DSC89J TI DSC89J PIN DIP U 7LS0 7LS0 PIN DIP U 7LS0 7LS0 PIN DIP U6 7HCT 7HCT 6 PIN DIP U7 7LS 7LS PIN DIP U8 7LS 7LS 6 PIN DIP U9 LM78LACZ TI LM78LACZ TO9 U0 LM79LACZ TI LM79LACZ TO9 U MAX809.8V ON SEMI MAX809MTRG SOT U NC7SZ86MX TinyLogic EOR FAIRCHILD NC7SZ86MX SOT- U LM80-. Gate. V LDO TI LM80IM SOT X XTAL.8 MHz Fox Electronics FOXLF08S Metal Can 0. Center Page 6