This program is Copyright © 1976 by HewlettPackard and is used here by permission. This program was originally published in the HP67 Games Pac 1.
This program is supplied without representation or warranty of any kind. HewlettPackard Company and The Museum of HP Calculators therefore assume no responsibility and shall have no liability, consequential or otherwise, of any kind arising from the use of this program material or any part thereof.
Game of 21 (Blackjack) 

Shift 
Shuffle 

New Player 

(next card) 
Label 
Bet> 
Hit 
Stand 
11 for Ace 
1 for Ace 
Key 
A 
B 
C 
D 
E 
You make your bet, and the calculator, as dealer, deals two cards to you and two to itself. You see the dealer's first card face up, then his second face down (the calculator shows 0). Your two cards are then shown face up, one at a time. Next, you see a number in the form XXX.YY, where XXX is your bet and YY is the number of points in your hand.
You and the dealer may draw additional cards. Your goal is to finish with a hand whose total count is 21 or below, but closer to 21 than the dealer's. If your hand totals over 21, you lose (you're "busted").
The King is indicated by 13, the Queen by 12, and the Jack by 11, but all count 10 points each. The other cards always count their face values except the Ace. The Ace counts 1 unless you decide to change it to an 11 (press D ). (If you have chosen 11 for an Ace, and want it counted 1, press E.). If the next card you draw makes your score over 21, the calculator will automatically check for an Ace and make it count 1 if you have chosen 11 for its value. Note that an Ace always counts 1 for the dealer, except for a blackjack. A blackjack is a 2 card hand totalling 21, made up of a 10, Jack, Queen, or King plus an Ace with a value of 11. Your best win is a blackjack, since you win 1.5 times your bet rather than the bet itself. If both you and the dealer get blackjack, you neither win nor lose, it's a "push."
After the initial deal, and provided neither you nor the dealer have blackjack, you may ask the dealer to give you another card ("hit") by pressing B. If you don't want to draw, you may "stand" by pressing C. The calculator will then show the dealer's two cards. If the dealer's (calculator's) hand counts 16 or less, it draws. It continues to draw until its hand totals 17 or more, then it stands.
The calculator then determines if you've won or lost, and blinks your winnings (XXX) or losses (XXX) and your final score (YY) in the form XXX.YY.
Next it shows your total account (the sum of your winnings and losses for all the games you've played this session).
Terms for HP67/97 Game of 21 (Blackjack)
Step 
Instructions 
Input Data/Units 
Keys 
Output Data/Units 
1 
Load side 1 and side 2. 

2 
Shuffle cards. 

f A 

3 
Stop shuffle and cut deck. 

R/S 
Ignore output 
4 
Input your bet (whole even dollars only  no cents nor odd dollars). Please do not bet over $100,000,000. 
Bet 
A 
Dealer's cards; 



your cards; 




Bet.points. 

5 
Hit (draw a card). 
B 
Bet.points. 

6 
Repeat step 5 until you are busted or you want to stand.  
7 
If you want your Ace scored as 11: 

D 
Bet.points. 
8 
If you want your Ace changed from 11 to 1: 

E 
Bet.points. 
9 
Stand 
C 
Win or Loss  
10 
If you had not chosen to stand, what would have bean your next card? 

f E 
Card 
11 
For a new game, go to step 2. 



12 
For a new player: Reset account to zero, and go to step 11. 

f C 
0.00 
Load sides 1 and 2.
Keystrokes Outputs f A Display will not stabilize until R/S is pressed. Wait 20 or 30 seconds. R/S Ignore output To reproduce the example below, store .9103987 in register E 100 A 9. *** Dealer's 1^{st} card 0. *** Dealer's 2^{nd} card (face down) 12. *** Your 1^{st} card is a Queen, worth 10 points. 7. *** Your 2^{nd} card 100.17 100 is your bet, 17 is your score. B 4. *** Your 3^{rd} card 100.21 Bet. Score C 9. *** Dealer's 1^{st} card 7. *** Dealer's 2^{nd} card 12. *** Dealer's 3^{rd} card 100.21 Your win. score display blinks to indicate end of game. Positive number means you win. 100.00 Your account 100 A 6. *** Dealer's 1^{st} card 0. *** Dealer's 2^{nd} card 1. *** Your 1^{st} card 7. *** Your 2^{nd} card 100.08 Your bet. score D 100.18 Your bet. score Your Ace is now counted as 11. You decide to stand. C 6. *** Dealer's 1^{st} card 12. *** Dealer's 2^{nd} card 4. *** Dealer's 3^{rd} card 100.18 Your loss. score 0.00 Your account
Dealer's 20 beats your 18, so you lose the $100 you won the first game. Care to try your luck again?
***Shown by PRINT on HP97 and by PAUSE on HP67.
LINE KEYS 001 *LBL A 002 PRT SPC 003 PRT SPC 004 CF 0 005 CF 1 006 STO A 007 1 008 STO I 009 GSB 0 010 STO B 011 GSB 5 012 GSB 9 013 STO 1 Bet, 014 STO 3 015 1 New game 016 STO I 017 GSB 0 018 STO C 019 GSB 9 020 STO 2 021 STO + 3 022 0 023 GSB 5 024 PRT SPC 025 GSB e 026 STO 5 027 STO 7 028 GSB e 029 STO 6 030 STO + 7 031 RCL 5 032 x 033 RCL 7 034 + 035 2 036 1 037 STO 0 038 X=Y? 039 GTO 2 040 RCL 7 041 GSB 3 042 R/S 043 *LBL B 044 GSB e 045 STO + 7 046 RCL 7 047 RCL 0 048 X<>Y Hit 049 X>Y? 050 GTO 4 051 X<=Y? 052 GSB 3 053 R/S 054 *LBL D 055 SF 0 056 1 057 0 058 STO + 7 11 for Ace 059 RCL 7 060 GSB 3 061 RTN 062 *LBL E 063 CF 0 064 1 065 0 066 STO  7 1 for Ace 067 RCL 7 068 GSB 3 069 RTN 070 *LBL 4 071 F0? 072 GTO E 073 RCL A 074 CHS 075 STO + 9 Player lose 076 RCL 7 077 EEX 078 2 079 ÷ 080  081 GTO 6 082 *LBL 2 083 RCL 1 084 RCL 2 085 x 086 RCL 3 HP Blackjack? 087 + 088 RCL 0 089 X=Y? 090 GTO 7 091 F1? 092 RTN 093 *LBL 8 094 . 095 2 096 1 097 RCL A Player Blackjack! 098 1 099 . 100 5 101 x 102 STO A 103 STO + 9 104 + 105 *LBL 6 106 PAUSE 107 PAUSE 108 PAUSE 109 PAUSE Display with blinks 110 RCL 9 111 DSP 2 112 F1? 113 R/S 114 RTN 115 *LBL 7 116 F1? 117 GTO 4 118 0 HP Blackjack! 119 DSP 9 120 GTO 6 121 *LBL 9 122 1 123 0 124 X<>Y 10 for J, Q, K 125 X<=Y? 126 RTN 127 X<>Y 128 RTN 129 *LBL 3 130 EEX 131 2 Display Bet.point 132 ÷ 133 RCL A 134 + 135 RTN 136 *LBL 5 137 DSP 0 138 PRTX Print 139 DSP 2 140 RTN 141 *LBL a 142 0 143 STO I 144 . 145 5 146 2 147 8 148 1 149 1 150 6 151 3 152 STO E 153 *LBL 0 Shuffle 154 RCL E 155 9 156 9 157 7 158 x 159 FRAC 160 STO E 161 1 162 3 163 x 164 INT 165 1 166 + 167 STO D 168 DSZ I 169 GTO 0 170 RTN 171 *LBL C 172 CF 0 173 PRT SPC 174 RCL B 175 GSB 5 176 RCL C 177 GSB 5 178 SF 1 179 GSB 2 180 CF 1 181 RCL 3 Stand and 182 *LBL b 183 1 HP takes cards 184 7 185 X<=Y? 186 GTO d 187 GSB e 188 STO + 3 189 RCL 3 190 2 191 2 192 X<=Y? 193 GTO 1 194 RCL 3 195 GTO b 196 *LBL d 197 RCL 7 198 RCL 3 199  200 X=0? 201 GTO 6 202 X<0? 203 GTO 4 204 *LBL 1 205 RCL A 206 STO + 9 207 RCL 7 208 GSB 3 209 GTO 6 210 *LBL e 211 1 212 STO I 213 GSB 0 Next card 214 GSB 5 215 GSB 9 216 RTN 217 *LBL c 218 0 New player 219 STO 9 220 RTN
R0 21 R1 1^{st} D R2 2^{nd} D R3 D R5 1^{st} P R6 2^{nd} P R7 P R9 Bet A Bet B 1^{st} D C 2^{nd} D D last K_{i} E u_{i} I Index
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