Personal Computer _. - - IBM 256KB Memory Expansion Option

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1 Personal Computer _. IBM 256KB Memory Expansion Option

3 Contents Description... 1 Switch-Configurable Start Address... 2 Operating Characteristics... 3 Voltage Requirements... 4 Specifications... 5 Logic Diagrams... 7 iii

4 Notes: iv

5 Description The IBM 256KB Memory Expansion Option is available for the IBM Personal Computer family of products. The system board must be populated to the maximum 256KB of RAM before the IBM 256KB Memory Expansion Option can be installed. The IBM 256KB Memory Expansion Option has four pluggable sockets. Each socket will accept a 64KB Memory Module, consisting of one (64K by 9) 32-pin D RAM Module. The 256KB expansion option comes with all four modules installed providing 256KB of memory. In addition to the memory modules, the memory expansion option contains the following circuits: bus buffering, dynamic memory timing generation, address repowering, and card-select decode logic. Dynamic-memory refresh timing and address generation are functions that are performed by the system board and made available in the I/O channel for all devices. The 256KB Memory Expansion Option is parity checked. If a parity error is detected, a latch is set and an I/O 'channel check' line is activated, indicating an error to the microprocessor. To allow the system unit to address the expanded memory provided by the IBM 256KB Memory Expansion Option, refer to the Guide to Operations manual for the proper memory-expansion-option switch settings. 2S6KB Memory Expansion Option 1

6 Switch-Configurable Start Address The 256KB Memory Expansion Option must be configured to reside at a sequential 64KB memory address boundary within the system address space. This is done by setting dual-in-line package (DIP) switches on the option. The IBM 256KB Memory Expansion Option has a small DIP module containing eight switches. The switches are used to set the card start address as follows: Number 256KB Options 1 ON: A19=O; OFF:A19=1 2 ON: A18=O; OFF:A18=1 3 ON: A17=O; OFF:A17=l 4 ON: A16=O; OFF:A16=1 5 ON: Select 64KB 6 ON: Select 128KB 7 ON: Select 192KB 8 ON: Select 256KB DIP Module Start Address 2 2S6KB Memory Expansion Option

7 The following method can be used to determine the switch settings for the 256KB memory expansion option. Starting Address = xxxkb 64KB = Decimal value xxxkb Convert decimal value to binary Bit Bit value Switch DODD O N t bit o 2 (off = logical 1) 3 Operating Characteristics The system board operates at a frequency of 4.77 MHz, which results in a clock cycle of 210 ns. Normally four clock cycles are required for a bus cycle so that an 840-ns memory cycle time is achieved. Memory-write and memory-read cycles both take four clock cycles, or 840 ns. 256KB Memory Expansion Option 3

8 Access and cycle times for memory used on the IBM 256KB Memory Expansion Option are: Time. Access Cycle 256KB Card 290 ns 840 ns Access/Cycle Times Voltage Requirements The IBM 256KB Memory Expansion card requires 3 voltage levels: + 12Vdc, +5Vdc, and -5Vdc KB Memory Expansion Option

9 Specific a tions This is the pin side view of the IBM 64K8 32-Pin D RAM Module. J9 H9 G9 F9 E9 09 C9 89 A9 t/beveled Edge J8 0 0 A8 J7 0 0 A7 J6 0 0 A6 JS 0 0 AS J4 0 0 A4 J3 0 0 A3 J2 0 0 A J1 H1 G1 F1 E1 01 C1 81 A1 Pin Signal Pin Signal Pin Signal Pin Signal A A14 J8 A1 81 +S.5 Vdc A2 03 C9 A09 J7 AO C1-2.2 Vdc A A11 J6 A A4 01 E9 A12 J5 A5 E1 06 A5 00 F9 A13 J4 A3 F1 07 A6 CS G9 RS J3 A2 G1 OS A7 OG 8 H9 A10 J2 A4 H1 +5Vdc AS OGA J9 A06 J1 GNO Ali AR The and -2.2Vdc are developed on the 256KB Memory Expansion Adapter. IBM 64KB Memory Module Pin Configuration 2S6KB Memory Expansion Option S

10 Notes: 6 256KB Memory Expansion Option

11 ) ) ) DiCKO 1.4 JI IrQ 7'1LSOI I DACKO PHD.. DAQ(O PM) (2) Q CD"SEL1i'E (2.3) ado PARITY (3) xrc 13) SELECT (2) SELECl (2) IrQ v a IMlwIII f til...!.iii ieiii ]812 DG (2) f IEMN lell f - " I 1'8 13: I... un : r G09 -R$ I I MOD 0,2 I I I I I R$ o UI1>'' "1:1 7'II..SC>I 8...:a 256KB Memory Expansion Option (Sheet 1 of 3) I I

12 QC N til =3: " A26 t'!'j '6 -= i.., = 0 "= Ct. 8 '0 "6." A16 A. A9 r::= 2 U20 3 AO_D A2S+ 3 U A6PRD A27+ A28+ A29+ A30 + '31 AIS A14 1:- i--'-=1as. PWO ldu20 - 'l A4PRWD Ul/ r VI? 8 6 A3 PRWO '2 PRWO 8 Al PRWD 6 A7 PRWO ')07 J09 1.)OS J02 JO'+ J03 Joe J06 '( 1 : 8.2K RHI : I I I I 5 4,3').2 sv iei6til IS IS 2 I" """ _ 8-2 :3 +SV I SV 6 UIS '3 +5'1 RH2 14 )0 n UI2 I I O '3 UI2..: 6 8.., "", IS I U12r---"',.-v..,.,..,"'"--- h =8 +SV.5oV 1J'7<4L S6KB I 14 6 I' : =.. U7 U4 10 -======= 17 64K9 SEL l'74l LS,. IJ,----.-sv LS :; +CDSELDEC 17 A23 + UI3m -NSI38 6 III 16 2'1$10 13 Is IUI2} I I S A U21 e A8 PRWO ----!:D 8 A9 PRIolO A09 (09 '5V 13 1<i CD SEL DEC I A21 13 U21 11 Al0 PRD 74LSCN HO':I 1 All,. A20... U216 AllPRWO ) ) U2) 3 S U5 6 -DGA <I o 6 '3 us JU2) 3 <:j 1 -DGA3 -DGA 2 -DGA 1 -DGB 4 A06 /0100 I A06 OD 0 A06 MOD) - SELECT (1) DACKO PWO (1) SELECT (1) (0 SEL DEC (1.3) A08 MOD MOD MOD 1 A08 MOD 0 A07 NOD 3 "2 AI.,,, 6 l II -DGB 3 A07 MOO DGB 2 Ala ;;; U18 II AI3 PRWO E09 12 U16 F09 UV 1.07 MOD I Ant 3 A14 PRlfIO U DGB I 1 2 ue 'NL532 A16+ ) AI5PR0 7 sv MOO 0 (1) DG 256KB Memory Expansion Option (Sheet 2 of 3) ) ) ) 0 I :

13 ) ) ) GIl).. I w2.2v '-..j-w-! In r ",.. r... '"" IlI e e-.. De ---e -.. '2 "I.rC20Ic,.r'io-I! 'roo,i ' 1 a --- ' ' =" D I e-- '" ". ---e - M.. -/,...,... r,... rt,l.iil'... '''''!)1 f'''s\i 1.1i!i1i!i "'" 2 :=:3 S. 'NLSI2"5.l FOOTPRINT OF t4er«ry /CXX.LE IQ) 0 IVIENEO TKn.IGH TI-E MOOU..E) "'", IQ)3 DO 2.. UIO IQ)'S 0-3 I " O U7 J DO I "NLS08 07 I -2.2 I.'5 HOI NCO I _r r III r.o;-:- t---!!20.., DO, DI -2.2 "!,. D2 : \e2., '" D) "06+7oIL,. 0- A05+ :.. '", DS :,.. DO '", I- D7 "'02+ 2 " l' 10 AN) S )00 o "C g f2) HI CXlD D) ':l U,'.ThFY DS EJ,J()I.. P.tTY 256KB Memory Expansion Option (Sheet 3 of 3)

14 Notes: KB Memory Expansion Option

IBM Personal Computer AT 128KB/640KB Memory Expansion Option

- - --- Personal Computer ---- - --- ----- - - - --- --_.- Hardware Reference Library IBM Personal Computer AT 128KB/640KB Memory Expansion Option 6183312 March 18, 1986 iv March 18, 1986 Contents Description...